A low-cost alternative for Ryzen systems to the high-calibre but higher-cost motherboards is the B350 range. Today we are testing the ASRock AB350 Gaming K4 motherboard, coming in under the radar just below $90. It offers almost everything its bigger cousins provide except SLI, but single GPU users can find a home with a motherboard like this one. Our aim today is to ascertain whether the ASRock AB350 Gaming K4 can be a top value proposition with the B350 chipset in play.

Other AnandTech Reviews for AMD’s Ryzen CPUs and X370/B350

The AMD Ryzen 3 1300X and Ryzen 3 1200 CPU Review: Zen on a Budget
The AMD Ryzen 5 1600X vs Core i5 Review: All Ryzen 5 CPUs Tested
The AMD Zen and Ryzen 7 Review: A Deep Dive on 1800X, 1700X and 1700

To read specifically about the X370/B350 chip/platform and the specifications therein, our deep dive into what it is can be found at this link.

Planned Reviews

• $260 - MSI X370 XPOWER GAMING TITANIUM
• $260 - ASRock X370 Professional Gaming
• $230 - ASRock X370 Taichi
• $175 - GIGABYTE AX370-Gaming 5 [review]
• $160 - ASRock X370 Gaming-ITX/ac
• $110 - Biostar X370GTN [review]
• $98 - MSI B350 Tomahawk [review]
• $90 - ASRock B350 Gaming K4 [this review]

The ASRock AB350 Gaming K4 Overview

Most of the world who own desktop computers typically have something very simple. A mid-range CPU, no overclock, a discrete graphics card, one or two storage devices, a modest memory, and a mouse/keyboard. Everyone likes to talk about the halo, but the reality is that the bigger battlefield is in the lower ranks. To that end, both major players offer non-overclockable mid-range CPUs, and also mid-range chipsets for motherboards that target a lower cost segment. A few of the extra features might be reduced, such as high-end USB ports, storage options, or SLI, but the benefit for the simpler system is lower cost, especially when in these markets, cost is a big factor in gaining market share. So alongside AMD's high end X370 is the more mid-range B350 and A320 chipsets, showing an awesome PC for most people doesn't have to empty the bank account.  

With the ASRock AB350 Gaming K4, as the name seems to imply, ASRock wants it two ways: a competitive gaming motherboard in the B350 chipset space. No idea why it is called the 'AB350', that's just something ASRock seems to do, but the goal of the board here is to target the gaming crowd. That means having a relatively fully black PCB, a set of red aluminium heatsinks, and a full-length PCIe slot for graphics that has extra reinforcement to take the toughest pixel pushing PCIe powerhouses. The top full-length slot runs in PCIe x16 mode from the CPU, while the second slot also from the CPU, but is limited to PCIe x4, and shares bandwidth with one of the M.2 slots.

Focusing on the storage, a total of six SATA 6Gb/s ports are present with four of them are angled at 90 degrees at the bottom right hand side of the board. The remaining two are straight angled and can be found towards the integrated USB 3.0 front panel header (at the foot of the four RAM slots); these two ports are powered through an ASMedia ASM1061 controller. The AB350 Gaming K4 has two M.2 slots, with the top one above the reinforced PCIe x16 Gen3 slot coming from the CPU, sharing PCIe lanes with the second full-length PCIe slot, while the second M.2 slot is a SATA-only slot. It's a shame that they both aren't PCIe, but still there are not many sub-$100 motherboards that will happily take two M.2 storage drives as easily.

The AB350 Gaming K4 does favour some of the more budget focused controllers, which which is to be expected on a sub $100 offering, but this means the onboard audio usese the Realtek RTL8111 networking chip and the Realtek ALC892 audio codec, often bundled at a discount for OEMs. The audio solution is reinforced by ELNA audio capacitors, as well as some degree of PCB separation to ensure there is no interference between the analog and digital signals in close proximity. Despite the chipset supporting USB 3.1 (10 Gbps), ASRock saves some effort in the mode complicated traces by relying on USB 3.0 instead - with five Type-A ports on the rear, a Type-C port on the rear enabled by an ASMedia ASM1543 redriver, and a single USB 3.0 header. Everything else is USB 2.0.

Despite this board, at this price point, is not exactly feature rich as shown by having only the four 4-pin fan headers. That being said, the dedicated CPU fan header does have support for a maximum power rating of 1A/12V, allowing for high-powered fans or pumps, and the other three fan headers are capable of automatically detecting if PWM or DC fans are connected.

Price wise, the ASRock AB350 Gaming K4 currently retails for a modest $90. This technically makes it one of the most expensive B350 motherboards on the market, however the value proposition is when comparing it to its more expensive X370 brethren. For the majority of gamers, such as those that do not need SLI support, the Gaming K4 has a lot to offer by shaving off some of those top tier items, but also comes bundled with ASRock's gaming software and capabilities. In the benchmarks, it draws close parity to its more expensive cousins, and even passes a good overclock. Why spend $250 on features the user might not need, when with a $90 motherboard the system can still offer a hefty punch - especially if that gets reinvested in a better GPU. 

Overclocking with a Ryzen 7 1700

Usually cheaper motherboards could lead to a variety of overclocking issues. For example, the power delivery could use cheaper components, resulting in a lower overall efficiency. This would empty more thermal energy into the heatsinks, and if the heatsinks are also similarly less performant due to cost, it compounts the issue. If the motherboard has fewer PCB layers, designers often have to make compromises on trace layout, which can also reduce potential peak frequencies.

Luckily, on the AB350 Gaming K4, overclocking was as easy as any of the X370 motherboards we have tested. The UEFI BIOS is very intuitive to use, and is one of my favourites so far out of all of the B350 based motherboards we have tested. One could quite easily forget that this isn’t actually an X370 motherboard in terms of performance, style, design and colour scheme. 

Methodology

Our standard overclocking methodology is as follows. We select the automatic overclock options and test for stability with POV-Ray and OCCT to simulate high-end workloads. These stability tests aim to catch any immediate causes for memory or CPU errors.

For manual overclocks, based on the information gathered from previous testing, starts off at a nominal voltage and CPU multiplier, and the multiplier is increased until the stability tests are failed. The CPU voltage is increased gradually until the stability tests are passed, and the process repeated until the motherboard reduces the multiplier automatically (due to safety protocol) or the CPU temperature reaches a stupidly high level (100ºC+). Our test bed is not in a case, which should push overclocks higher with fresher (cooler) air.

Overclocking Results

From our previous testing, our Ryzen 7 1700 CPU has a limitation between 3.9 GHz and 4.0 GHz. Despite the hub-bub over 4 GHz and above Ryzen chips, while 3.9GHz seems meagre, in the full spectrum of the silicon lottery it is actually reasonable for a Ryzen 7 1700 chip. Even at 3.9 GHz, the performance is consistent within our testing perameters, with the chip pushing close to 190 W at the wall under OCCT.

The Ryzen 7 1700 processor we are currently using has a 3.0 GHz base core clock with a turbo clock speed of 3.7 GHz, and has an on-the-box TDP of 65W. When overclocked to 3.9 GHz with 1.375 volts, the overall power consumption taken at the wall was pushing just under 189W at peak, but it sailed through our testing.

ASRock AB350 Gaming K4 Board Features

While 2-way CrossFireX is technically possible with the AB350 Gaming K4, I would advise against it due to the bandwidth limitations on the second full-length PCIe slot; this is electrically wired to run at x4 mode at all times and shares bandwidth with the top M.2 slot.

ASRock AB350 Gaming K4 ATX Motherboard
Warranty Period	3 Years
Product Page	Link
Price	$90
Size	ATX
CPU Interface	AM4
Chipset	AMD B350
Memory Slots (DDR4)	Four DDR4 Supporting 64GB Dual Channel Up to 3200 MHz
Video Outputs	HDMI 1.4, DVI-D, D-Sub
Network Connectivity	Realtek RTL8111GR
Onboard Audio	Realtek ALC892
PCIe Slots for Graphics (from CPU)	1 x PCIe 3.0 (x16) 1 x PCIe 3.0 (x4) - shares with M.2
PCIe Slots for Other (from PCH)	1 x PCIe 2.0 (x4) 4 x PCIe (x1)
Onboard SATA	Four, RAID 0/1/10
Onboard M.2	1 x PCIe 3.0 x4 (top slot) 1 x SATA 6Gb/s (bottom slot)
USB 3.1 (10 Gbps)	N/A
USB 3.0 (5 Gbps)	1 x Type-C 5 x Rear Panel (Type-A) 2 via Header
USB 2.0	2 x Type-A 4 via Header
Power Connectors	1 x 24-pin ATX 1 x 8-pin CPU
Fan Headers	1 x CPU (4-pin) 3 x System (4-pin)
IO Panel	5 x USB 3.1 Type-A (USB 3.1 Gen 1) 1 x USB 3.1 Type-C (USB 3.1 Gen 1) 2 x USB 2.0 Type-A 1 x Network RJ-45 1 x HDMI 1.4 1 x Combo PS/2 3 x 3.5 mm Audio Jacks

The emphasis is primarily on gaming with ASRocks contunuing partnership with Fatal1ty, for whatever that seems to be worth these days. $90 means there has to be some cut backs compared to the high-end products, so we see the audio/networking combination from Realtek which is often sold at a combined discount to motherboard manufacturers. 

Visual Inspection

The ASRock AB350 Gaming K4 does feature an element of customization through a set of red LEDs placed underneath the PCH heatsink which can be controlled via the BIOS, or with the ASRock RGB utility app. Users looking for RGB connectivity will be happy to know a single RGB LED header has been implemented, as well as a dedicated LED fan header. Following this, the AB350 Gaming K4 has a dedicated CPU fan 4-pin header with a further three 4-pin headers for system fans. Power to the CPU comes through an 8-pin 12V power connector with auxiliary power to the motherboard coming via the standard 24-pin ATX connector.

Memory support is a plenty and thanks to the wave of AGESA BIOS updates that rolled out last year. The four RAM slots operate in dual channel mode and has support for a total of 64 GB of DDR4 memory with speeds up to DDR4-3200.

Making up the power delivery on this board is an Intersil ISL95712 PWM controller with three initial drivers for the CPU which have doublers to make the total amount physical phases dedicated to the CPU at six. The ISL95712 on paper can only handle four in total, so an additional Intersil ISL6625 driver is featured. Sinopower SM4336 and SM4337 MOSFETs make up the SOC and CPU sections of the power delivery, which aren't the most efficient choices in the grand scheme of things, but these are more than capable of handling an eight core Ryzen CPU with a modest overclock such as the Ryzen 7 1700 used in our AM4 motherboard reviews. In addition to this, there is a single Anpec APW8720B driver taking care of the memory.

Just peering at the VRM heatsinks a little bit better, they don’t seem anything overly special, but they certainly kept their cool with our Ryzen 7 1700 running at 3.9 GHz. The only caveat with them is the use of plastic push pins which I’m not a massive fan of. Not just from a robustness/quality point of view, but they only apply so much pressure between them, the thermal pad and heatsinks themselves. MSI’s B350 Tomahawk uses screws and I much prefer this method of fixing to simple plastic pins. But everything has a price, right?

The PCI layout and configuration on the AB350 Gaming K4 gives two full-length PCIe slots, with the top one running at PCIe 3.0 x16 from the CPU and reinforced for heavy graphics cards. The second full-length slot is a PCIe 3.0 x4 connection, also from the CPU, but shares bandwidth with the top M.2 slot. The other four shorter PCIe slots are PCIe 2.0 x1 from the chipset.

Touching more on the storage options, ASRock has achieved dual M.2 ports on this board which if needed, is there to be used. This is something not usually seen on lower costed boards, but there is some sharing going on: if a user has a drive in the second M.2 slot at the bottom of the board, this slot shares lanes with the third SATA port and if one is in use, the other will be disabled and visa versa. Rounding off the storage are four right angled SATA ports and two straight angled SATA ports. The pair of straight angled ports are controlled by the ASMedia ASM1061 controller, while the four right angled take adage from the chipset itself. The SATA ports have support for RAID 0, 1 and 10.

On the rear panel, the AB350 Gaming K4 has a very similar layout to the competition with the main difference being the inclusion of a further two USB 3.1 Gen1 more than the Tomahawk. This gives the ASRock option a total of five USB 3.1 Gen1 Type-A ports, one USB 3.1 Type-C port, and a further two USB 2.0 included. A combo PS/2 keyboard and mouse port sits just below the USB 2.0, with a section dedicated to utilizing the new Raven Ridge APUs onboard graphic capabilities thanks to a D-sub, HDMI and DVI-D slot being featured; the VGA is controlled by the Realtek RTD2168. The single LAN port is controlled by the Realtek RTL8111GR with the three 3.5mm audio inputs from the Realtek ALC892 codec. There is a distinct lack of USB 3.1 Gen2 ports anywhere on the board, despite the chipset support, but this purely comes down to cost.

In the Box

The ASRock AB350 Gaming K4 has a relatively basic set of accessories, but from a logical stand point, it's to be expected given the low cost overall.

We get the following:

• Driver Disk
• UEFI BIOS & Quick Start guide
• Rear I/O Plate
• Two SATA 6 Gbps Cables (One right angled and one straight)
• Two Installation screws for M.2 drives

BIOS

ASRock has gone with a fairly basic but enthusiast-oriented BIOS that features a black and red theme. The ASRock BIOS implementation is, as an enthusiast, one of the more intuitive BIOSs on the B350 chipset I have encountered thus far. The different panels themselves are grey with white writing across the entirety of the BIOS, giving it a subtle, yet rather gaming style theme. You know, because 'gaming' is defined as red and black.

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Upon first look at the main entry screen, as there is no EZ mode, a list of vital information can be found including RAM statistics from each DIMM (no timings however), as well as the processor type and BIOS firmware version currently installed. As mentioned, this board can support up to 64GB of memory.

As it currently stands, no B350 chipset board on the market has an external clock generator meaning the base clock cannot be altered. It’s not exactly a surprise, but what did actually slightly shock me was the sheer number of options for overclocking. It goes to show that B350 isn’t all too dissimilar in regards to performance over X370 and aside from the cost cutting to make the platform cheaper, ASRock has made no shortcuts in regards to the BIOS. Memory modules with XMP profiles do feature support, but as the specifications of the Gaming K4 state, a maximum memory speed of DDR4-3200 is potentially going to be the limit depending on the strength of your CPUs memory controller.

One relatively handy thing the ASRock has going for them in their BIOS comes in the storage section. The specifications do openly state that the second M.2 slot shares bandwidth with SATA slot three, but it’s even clearer when looking in the BIOS that both are in fact linked, and will only detect one or the other, so bear that in mind.

If a user doesn't want to make use of the LED control options via software, they can do this directing in the BIOS, although unless they know the desired 0-255 number required for red, green, and blue, it can be a little bit more difficult. The LEDs underneath the PCH heatsink do only glow red, but depending on the users taste, a separate RGB header is present meaning use of compatible RGB strips can be installed. The LED control in the BIOS could really do with an overhaul for RGB products, but I would advise for the best results, to use the ASRock RGB LED software that comes with the CD; or alternatively you can download the latest version from the ASRock website.

To be constructive, there are things ASRock can do to enhance usability such as rework their built-in RGB options within the BIOS, but it works well and does everything you would expect of a board of this caliber.

Software

It shouldn’t come as any surprise that a motherboard SKU with ‘Gaming’ in the title should focus on the key market it’s been specifically designed for. ASRock are known for their user friendly and sometimes technically sound applications (such as OC Tuner), but the AB350 Gaming K4, aside from the necessary core basic applications, does not have much extra. Avialable applications include the F-Stream overclocking utility, which is geared towards enthusiast overclockers than the regular user, the APP shop, ASRock RGB LED, and the Sound Blaster Cinema 3 audio application.

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Probably the most notable of the supported software applications is the Sound Blaster 3 utility from Creative. The software itself allows for the enablement, or disablement, of functions such as SBX Surround, which is designed to increase the realistic nature of the audio played. It’s a pretty intuitive feature and aside from the ability to create your own custom sound profiles, they do include pre-sets for things like gaming, music, movies etc. Another smart feature is SBX smart volume which moderates the volume to avoid large spikes which can cause ear discomfort.

The other handy application is the ASRock RGB LED software. It does exactly what it says on the tin and allows users to customize the fan via the AMD RGB fan header, as well as through the single RGB header (non-addressable). The red-only LEDs under the PCH heatsink can be switched off or customized into changing the style from static, to flashing, to breathing etc.

Test Bed

As per our testing policy, we take a high-end CPU suitable for the motherboard that was released during the socket’s initial launch, and equip the system with a suitable amount of memory running at the processor maximum supported frequency. This is also typically run at JEDEC subtimings where possible. It is noted that some users are not keen on this policy, stating that sometimes the maximum supported frequency is quite low, or faster memory is available at a similar price, or that the JEDEC speeds can be prohibitive for performance. While these comments make sense, ultimately very few users apply memory profiles (either XMP or other) as they require interaction with the BIOS, and most users will fall back on JEDEC supported speeds - this includes home users as well as industry who might want to shave off a cent or two from the cost or stay within the margins set by the manufacturer. Where possible, we will extend out testing to include faster memory modules either at the same time as the review or a later date.

Test Setup
Processor	AMD Ryzen 7 1700, 65W, $300, 8 Cores, 16 Threads, 3GHz (3.7GHz Turbo)
Motherboard	ASRock AB350 Gaming K4 (BIOS F9a)
Cooling	Thermaltake Floe Riing RGB 360
Power Supply	Thermaltake Toughpower Grand 1200W Gold PSU
Memory	2x16GB Corsair Vengeance LPX DDR4-2400
Video Card	ASUS GTX 980 STRIX (1178/1279 Boost)
Hard Drive	Crucial MX300 1TB
Case	Open Test Bed
Operating System	Windows 10 Pro

Readers of our motherboard review section will have noted the trend in modern motherboards to implement a form of MultiCore Enhancement / Acceleration / Turbo (read our report here) on their motherboards. This does several things, including better benchmark results at stock settings (not entirely needed if overclocking is an end-user goal) at the expense of heat and temperature. It also gives, in essence, an automatic overclock which may be against what the user wants. Our testing methodology is ‘out-of-the-box’, with the latest public BIOS installed and XMP enabled, and thus subject to the whims of this feature. It is ultimately up to the motherboard manufacturer to take this risk – and manufacturers taking risks in the setup is something they do on every product (think C-state settings, USB priority, DPC Latency / monitoring priority, overriding memory sub-timings at JEDEC). Processor speed change is part of that risk, and ultimately if no overclocking is planned, some motherboards will affect how fast that shiny new processor goes and can be an important factor in the system build.

Many thanks to...

Thank you to ASUS for providing us with GTX 980 Strix GPUs. At the time of release, the STRIX brand from ASUS was aimed at silent running, or to use the marketing term: '0dB Silent Gaming'. This enables the card to disable the fans when the GPU is dealing with low loads well within temperature specifications. These cards equip the GTX 980 silicon with ASUS' Direct CU II cooler and 10-phase digital VRMs, aimed at high-efficiency conversion. Along with the card, ASUS bundles GPU Tweak software for overclocking and streaming assistance.

The GTX 980 uses NVIDIA's GM204 silicon die, built upon their Maxwell architecture. This die is 5.2 billion transistors for a die size of 298 mm2, built on TMSC's 28nm process. A GTX 980 uses the full GM204 core, with 2048 CUDA Cores and 64 ROPs with a 256-bit memory bus to GDDR5. The official power rating for the GTX 980 is 165W.

The ASUS GTX 980 Strix 4GB (or the full name of STRIX-GTX980-DC2OC-4GD5) runs a reasonable overclock over a reference GTX 980 card, with frequencies in the range of 1178-1279 MHz. The memory runs at stock, in this case 7010 MHz. Video outputs include three DisplayPort connectors, one HDMI 2.0 connector and a DVI-I.

Further Reading: AnandTech's NVIDIA GTX 980 Review

Thank you to Crucial for providing us with MX200/MX300 SSDs. Crucial stepped up to the plate as our benchmark list grows larger with newer benchmarks and titles, and the 1TB units are strong performers. The MX200s are based on Marvell's 88SS9189 controller and using Micron's 16nm 128Gbit MLC flash, these are 7mm high, 2.5-inch drives rated for 100K random read IOPs and 555/500 MB/s sequential read and write speeds. The 1TB models we are using here support TCG Opal 2.0 and IEEE-1667 (eDrive) encryption and have a 320TB rated endurance with a three-year warranty.

Further Reading: AnandTech's Crucial MX200 (250 GB, 500 GB & 1TB) Review

Thank you to Corsair for providing us with Vengeance LPX DDR4 Memory

Corsair kindly sent a set of their Vengeance LPX low profile, high-performance memory. The heatsink is made of pure aluminum to help remove heat from the sticks and has an eight-layer PCB. The heatsink is a low profile design to help fit in spaces where there may not be room for a tall heat spreader; think a SFF case or using a large heatsink.

Benchmark Overview

For our testing, depending on the product, we attempt to tailor the presentation of our global benchmark suite down into what users who would buy this hardware might actually want to run. For CPUs, our full test suite is typically used to gather data and all the results are placed into Bench, our benchmark database for users that want to look at non-typical benchmarks or legacy data. For motherboards, we run our short form CPU tests and our system benchmark tests which focus on non-typical and non-obvious performance metrics that are the focal point for specific groups of users.

The benchmarks fall into several areas:

Short Form CPU

Our short form testing script uses a straight run through of a mixture of known apps or workloads, and requires about four hours. These are typically the CPU tests we run in our motherboard suite, to identify any performance anomalies.

CPU Short Form Benchmarks
Three Dimensional Particle Movement v2.1 (3DPM)	3DPM is a self-penned benchmark, derived from my academic research years looking at particle movement parallelism. The coding for this tool was rough, but emulates the real world in being non-CompSci trained code for a scientific endeavor. The code is unoptimized, but the test uses OpenMP to move particles around a field using one of six 3D movement algorithms in turn, each of which is found in the academic literature.
	The second version of this benchmark is similar to the first, however it has been re-written in VS2012 with one major difference: the code has been written to address the issue of false sharing. If data required by multiple threads, say four, is in the same cache line, the software cannot read the cache line once and split the data to each thread - instead it will read four times in a serial fashion. The new software splits the data to new cache lines so reads can be parallelized and stalls minimized.
WinRAR 5.4	WinRAR is a compression based software to reduce file size at the expense of CPU cycles. We use the version that has been a stable part of our benchmark database through 2015, and run the default settings on a 1.52GB directory containing over 2800 files representing a small website with around thirty half-minute videos. We take the average of several runs in this instance.
POV-Ray 3.7.1 b4	POV-Ray is a common ray-tracing tool used to generate realistic looking scenes. We've used POV-Ray in its various guises over the years as a good benchmark for performance, as well as a tool on the march to ray-tracing limited immersive environments. We use the built-in multithreaded benchmark.
HandBrake v1.0.2	HandBrake is a freeware video conversion tool. We use the tool in to process two different videos into x264 in an MP4 container - first a 'low quality' two-hour video at 640x388 resolution to x264, then a 'high quality' ten-minute video at 4320x3840, and finally the second video again but into HEVC. The low-quality video scales at lower performance hardware, whereas the buffers required for high-quality tests can stretch even the biggest processors. At current, this is a CPU only test.
7-Zip 9.2	7-Zip is a freeware compression/decompression tool that is widely deployed across the world. We run the included benchmark tool using a 50MB library and take the average of a set of fixed-time results.
DigiCortex v1.20	The newest benchmark in our suite is DigiCortex, a simulation of biologically plausible neural network circuits, and simulates the activity of neurons and synapses. DigiCortex relies heavily on a mix of DRAM speed and computational throughput, indicating that systems which apply memory profiles properly should benefit and those that play fast and loose with overclocking settings might get some extra speed up.

System Benchmarks

Our system benchmarks are designed to probe motherboard controller performance, particularly any additional USB controllers or the audio controller. As general platform tests we have DPC Latency measurements and system boot time, which can be difficult to optimize for on the board design and manufacturing level.

System Benchmarks
Power Consumption	One of the primary differences between different motherboards is power consumption. Aside from the base defaults that every motherboard needs, things like power delivery, controller choice, routing, and firmware can all contribute to how much power a system can draw. This increases for features such as PLX chips and multi-gigabit ethernet.
Non-UEFI POST Time	The POST sequence of the motherboard becomes before loading the OS, and involves pre-testing of onboard controllers, the CPU, the DRAM and everything else to ensure base stability. The number of controllers, as well as firmware optimizations, affect the POST time a lot. We test the BIOS defaults as well as attempt a stripped POST.
Rightmark Audio Analyzer 6.2.5	Testing onboard audio is difficult, especially with the numerous amount of post-processing packages now being bundled with hardware. Nonetheless, manufacturers put time and effort into offering a 'cleaner' sound that is loud and of a high quality. RMAA, with version 6.2.5 (newer versions have issues), under the right settings can be used to test the signal-to-noise ratio, signal crossover, and harmonic distortion with noise.
USB Backup	USB ports can come from a variety of sources: chipsets, controllers or hubs. More often than not, the design of the traces can lead to direct impacts on USB performance as well as firmware level choices relating to signal integrity on the motherboard.
DPC Latency	Another element is deferred procedure call latency, or the ability to handle interrupt servicing. Depending on the motherboard firmware and controller selection, some motherboards handle these interrupts quicker than others. A poor result could lead to delays in performance, or for example with audio, a delayed request can manifest in distinctly audible pauses, pops or clicks.

System Performance

Not all motherboards are created equal. On the face of it, they should all perform the same and differ only in the functionality they provide - however, this is not the case. The obvious pointers are power consumption, but also the ability for the manufacturer to optimize USB speed, audio quality (based on audio codec), POST time and latency. This can come down to manufacturing process and prowess, so these are tested.

Power Consumption

Power consumption was tested on the system while in a single ASUS GTX 980 GPU configuration with a wall meter connected to the Thermaltake 1200W power supply. This power supply has ~75% efficiency > 50W, and 90%+ efficiency at 250W, suitable for both idle and multi-GPU loading. This method of power reading allows us to compare the power management of the UEFI and the board to supply components with power under load, and includes typical PSU losses due to efficiency. These are the real world values that consumers may expect from a typical system (minus the monitor) using this motherboard.

While this method for power measurement may not be ideal, and you feel these numbers are not representative due to the high wattage power supply being used (we use the same PSU to remain consistent over a series of reviews, and the fact that some boards on our test bed get tested with three or four high powered GPUs), the important point to take away is the relationship between the numbers. These boards are all under the same conditions, and thus the differences between them should be easy to spot.

In idle and long idle power states, the AB350 Gaming K4 sits with the lowest numbers out of the AM4 boards tested thus far, but this is most likely due to how sparse the PCB which is attested to how basic a model this board actually is in comparison to some in the graphs. At load, we get results similar to other ATX motherboards in this space.

Non-UEFI POST Time

Different motherboards have different POST sequences before an operating system is initialized. A lot of this is dependent on the board itself, and POST boot time is determined by the controllers on board (and the sequence of how those extras are organized). As part of our testing, we look at the POST Boot Time using a stopwatch. This is the time from pressing the ON button on the computer to when Windows starts loading. (We discount Windows loading as it is highly variable given Windows specific features.)

The majority of the POST times seem to align with each other within a second or two, although turning the controllers off didn't make any difference.

Rightmark Audio Analyzer 6.2.5

Rightmark:AA indicates how well the sound system is built and isolated from electrical interference (either internally or externally). For this test we connect the Line Out to the Line In using a short six inch 3.5mm to 3.5mm high-quality jack, turn the OS speaker volume to 100%, and run the Rightmark default test suite at 192 kHz, 24-bit. The OS is tuned to 192 kHz/24-bit input and output, and the Line-In volume is adjusted until we have the best RMAA value in the mini-pretest. We look specifically at the Dynamic Range of the audio codec used on the rear panel of the board.

The trend of performance is clear in the above graph, especially when the ALC1220 laden boards sit consistently higher in dynamic range than the more cost effective ALC892 codecs.

DPC Latency

Deferred Procedure Call latency is a way in which Windows handles interrupt servicing. In order to wait for a processor to acknowledge the request, the system will queue all interrupt requests by priority. Critical interrupts will be handled as soon as possible, whereas lesser priority requests such as audio will be further down the line. If the audio device requires data, it will have to wait until the request is processed before the buffer is filled.

If the device drivers of higher priority components in a system are poorly implemented, this can cause delays in request scheduling and process time. This can lead to an empty audio buffer and characteristic audible pauses, pops and clicks. The DPC latency checker measures how much time is taken processing DPCs from driver invocation. The lower the value will result in better audio transfer at smaller buffer sizes. Results are measured in microseconds.

None of the manufacturers we have seen so far on B350/X370 have optimized their boards for DPC latency, but each board consistently remained below 150 microseconds. All three of the ASRock options tested perform well, even the low cost AB350 Gaming K4 on review today.

CPU Performance, Short Form

For our motherboard reviews, we use our short form testing method. These tests usually focus on if a motherboard is using MultiCore Turbo (the feature used to have maximum turbo on at all times, giving a frequency advantage), or if there are slight gains to be had from tweaking the firmware. We put the memory settings at the CPU manufacturers suggested frequency, making it very easy to see which motherboards have MCT enabled by default.

Video Conversion – Handbrake v1.0.2: link

Handbrake is a media conversion tool that was initially designed to help DVD ISOs and Video CDs into more common video formats. For HandBrake, we take two videos and convert them to x264 format in an MP4 container: a 2h20 640x266 DVD rip and a 10min double UHD 3840x4320 animation short. We also take the third video and transcode it to HEVC. Results are given in terms of the frames per second processed, and HandBrake uses as many threads as possible.

Compression – WinRAR 5.4: link

Our WinRAR test from 2013 is updated to the latest version of WinRAR at the start of 2017. We compress a set of 2867 files across 320 folders totaling 1.52 GB in size – 95% of these files are small typical website files, and the rest (90% of the size) are small 30 second 720p videos.

Point Calculations – 3D Movement Algorithm Test v2.1: link

3DPM is a self-penned benchmark, taking basic 3D movement algorithms used in Brownian Motion simulations and testing them for speed. High floating point performance, MHz and IPC wins in the single thread version, whereas the multithread version has to handle the threads and loves more cores. For a brief explanation of the platform agnostic coding behind this benchmark, see my forum post here. We are using the latest version of 3DPM, which has a significant number of tweaks over the original version to avoid issues with cache management and speeding up some of the algorithms.

Rendering – POV-Ray 3.7.1b4: link

The Persistence of Vision Ray Tracer, or POV-Ray, is a freeware package for as the name suggests, ray tracing. It is a pure renderer, rather than modeling software, but the latest beta version contains a handy benchmark for stressing all processing threads on a platform. We have been using this test in motherboard reviews to test memory stability at various CPU speeds to good effect – if it passes the test, the IMC in the CPU is stable for a given CPU speed. As a CPU test, it runs for approximately 2-3 minutes on high end platforms.

Synthetic – 7-Zip 9.2: link

As an open source compression tool, 7-Zip is a popular tool for making sets of files easier to handle and transfer. The software offers up its own benchmark, to which we report the result.

Gaming Performance

Ashes of the Singularity

Seen as the holy child of DirectX12, Ashes of the Singularity (AoTS, or just Ashes) has been the first title to actively go explore as many of DirectX12s features as it possibly can. Stardock, the developer behind the Nitrous engine which powers the game, has ensured that the real-time strategy title takes advantage of multiple cores and multiple graphics cards, in as many configurations as possible.

Rise Of The Tomb Raider

Rise of the Tomb Raider is a third-person action-adventure game that features similar gameplay found in 2013's Tomb Raider. Players control Lara Croft through various environments, battling enemies, and completing puzzle platforming sections, while using improvised weapons and gadgets in order to progress through the story.

One of the unique aspects of this benchmark is that it’s actually the average of 3 sub-benchmarks that fly through different environments, which keeps the benchmark from being too weighted towards a GPU’s performance characteristics under any one scene.

Thief

Thief has been a long-standing title in PC gamers hearts since the introduction of the very first iteration which was released back in 1998 (Thief: The Dark Project). Thief as it is simply known rebooted the long-standing series and renowned publisher Square Enix took over the task from where Eidos Interactive left off back in 2004. The game itself utilises the fluid Unreal Engine 3 engine and is known for optimised and improved destructible environments, large crowd simulation and soft body dynamics.

Total War: WARHAMMER

Not only is the Total War franchise one of the most popular real-time tactical strategy titles of all time, but Sega delve into multiple worlds such as the Roman Empire, Napoleonic era and even Attila the Hun, but more recently they nosedived into the world of Games Workshop via the WARHAMMER series. Developers Creative Assembly have used their latest RTS battle title with the much talked about DirectX 12 API so that this title can benefit from all the associated features that comes with it. The game itself is very CPU intensive and is capable of pushing any top end system to their limits.

ASRock AB350 Gaming K4 Conclusion

The ASRock AB350 Gaming K4 is specifically aimed at gamers on the cheaper side of the market: those who only need a single GPU and stndard functionality. ASRock gets straight to the heart of the matter here, having a single PCIe 3.0 x16 slot that is reinforced, ready to take on any triple-slot behemoth that was purchased with the $$$ saved. The key headlines about B350 boards is price: if you can forgo SLI, are happy with 'standard' audio and networking, only need four SATA ports, and don't need USB 3.1 10 Gbps ports (as in this case, but the chipset supports them), then that extra money can be focused elsewhere for a gaming build.

In regards to the performance, there wasn’t any problems or irregularities during testing and I’m more than happy with the quality and fluidity of the BIOS. It’s clear that ASRock has made the AB350 Gaming K4 for gamers wanting an affordable Ryzen based system, but without capitulating the B350 chipset with bargain basement or inadequate components. The power delivery might not be the most potent of layouts, but it was more than adequate to keep an eight-core Ryzen 7 1700 with a modest overclock without having to worry about it. This is due to the Intersil ISL95712 PWM controller, which is found on other boards including the GIGABYTE AB350 Gaming 3 ($80) and even the ASRock X370 Gaming ITX/ac ($180) motherboard. The power delivery operates in an 8+3 configuration and is complimented by Sinopower SM4336 and SM4337 MOSFETs which makes up the bulk of space in the VRM area.

The AB350 Gaming K4 has a total of four native SATA 6Gb/s ports with support for RAID 0, 1 and 10, and another two ports from an ASMedia controller. In addition to the SATA, the board has two M.2 slots, which is impressive to find on such a value focused motherboard. Of course, the caveat here is the top M.2 slot does share bandwidth with the bottom PCIe x4 slot, and the second M.2 is SATA only. 

One thing I would like to see included is an easy connector for the front panel pins, as the onboard guide is not as simple as it first appears. If the user is not entirely familiar with the pin out, the manual would be a great starting point, which means digging it out of the box (and so few people look at the manual anyway). The patience of people seems to be getting thinner and thinner within the building community and time saving devices such as an easy connector could enhance the users overall experience.

The BIOS on the AB350 Gaming K4 is very intuitive to enthusiasts, and enables enough overclocking options for those with experience to get to grips. Unfortunately, for users not so confident, there are no automatic overclocking methods featured, other than XMP. This board can accommodate DDR4 RAM up to a total capacity of 64GB (four 16GB modules) with speeds supported up to a maximum of DDR4-3200. This isn’t the theoretical limit on Ryzen for memory, but this will entirely depend on the integrated memory controller of the processor.

With a focus on value, ASRock has indeed included a single USB 3.0 Type-C port, enabled by an ASMedia ASM1543 redriver, as well as five USB 3.0 Type-A ports. For users investing in the new Ryzen Raven Ridge APUs, ASRock has supplied a HDMI port, a DVI-D port and a VGA port.

Audio wise, this board has a Realtek ALC892 codec, which gives the rear panel a total of three 3.5mm jacks; the ALC892 codec doesn’t support the use of a S/PDIF output, but on a board targeted directly at budget gamers, this can be forgiven. Finishing off the rear panel is a single Gigabit Ethernet (RJ45) port controlled by the Realtek RTL8111GR Gigabit controller.

The ASRock AB350 Gaming K4 has enough to make it a very worthwhile purchase for gamers with single graphics cards wanting to save a bit of money over the X370 chipset, but without sacrificing much in the way of onboard qualities. There are a few options that perhaps wouldn't go amiss, such as USB 3.1 support, but the motherboard at this price certainly has no issue keeping up in 24/7 performance with the best of them. 

 

Other AMD X370 / B350 Motherboards We Have Tested

• $260 - MSI X370 XPOWER GAMING TITANIUM
• $260 - ASRock X370 Professional Gaming
• $230 - ASRock X370 Taichi
• $175 - GIGABYTE AX370-Gaming 5 [review]
• $160 - ASRock X370 Gaming-ITX/ac
• $110 - Biostar X370GTN [review]
• $98 - MSI B350 Tomahawk [review]
• $90 - ASRock B350 Gaming K4 [this review]