Original Link: https://www.anandtech.com/show/129

Many thought the Socket-7 Motherboard World was dead after the release of Intel's Pentium II, which required a new type of motherboard based on a Slot CPU interface, called Slot-1.  Others believed that Socket-7 still had a bit of energy left in it and was just waiting for the right processor to breathe some life into the aging standard.  For those of you that have been patient, the wait is finally over, that very processor has come along: Advanced Micro Devices' K6-2.  The glimmer at what seemed to be the end of the Socket-7 tunnel is revealing a completely new world outside of the confinements of darkness.

With the BX motherboards out on the market today, you could pretty much choose just about any BX motherboard out there and be pleased with your system overall.  Unfortunately that is not the case with Socket-7 AGP/Super7 motherboards.  There are many other factors to consider aside from whether or not a motherboard supports a certain FSB setting, this is where things get more complicated.  There are three different companies competing for the same ground with their Socket-7 AGP/Super7 chipsets, all with their own strengths, weaknesses, and each one tailored to suit a different individual user.  When dealing with Slot-1 motherboards, there is one and only one real choice, BX all the way.  Now, in a more complex, and potentially powerful motherboard market, armed with the untamed power of the AMD K6-2 making a decision as to which Socket-7/Super7 motherboard is right for you can be quite difficult.  Let's see which motherboard(s) come out on top as AnandTech compares 10 of the best Socket-7 AGP/Super7 motherboards on the market today...

Processors

For those of you planning to use your system strictly for purposes of Net Surfing, Business Applications such as Microsoft Office and other such office suites, and so forth your options are as open as the skies above you.  Any Socket-7 processor would really suit your needs in that case, with the top two options being the Intel Pentium MMX and the AMD K6 as your top two options for future use in the months to come.  If you aren't limited by a processor choice then your motherboard choices are just as broad, unfortunately very few of us are blessed with so many choices...which leads us to the next topic. 

Once you add more advanced applications and therefore more demanding ones, you begin to limit your choices of processors, and in turn you limit your motherboard sample set.  For quite some time the only real option for a gamer or someone looking to get the most out of their 3D games was a Pentium MMX or a Pentium II (more recently the Intel Celeron), however since those days things have dramatically changed.  AMD now poses a major threat to Intel's gaming throne with their next generation K6 processors running at clock speeds in excess of 266MHz, and with their K6-2 processors able to produce Pentium II levels of gaming as well as Business and High End performance.  For the user that wants it all, yet doesn't have all that much to spend, the best overall option (provided you are an avid gamer) would be a K6-2 + Super7 motherboard combination.  With the Pentium MMX as a secondary choice if you already have a processor and are simply looking for a motherboard upgrade. 

Chipsets

With the processor decided upon, you must decide what chipset you want to have on your motherboard.  The chipset is basically the communication medium for the entire motherboard, it is what allows the processor to "talk to" the rest of the components on the motherboard such as the Memory (RAM), Video Card, and other such devices.  The chipset essentially deems which luxury options your system will support once it is complete, for example, only certain chipsets support the Accelerated Graphics Port (AGP) and only certain chipsets support the Ultra-ATA Hard Disk Specification.  All of the chipsets featured on the motherboards compared here boast full AGP compliance and support the UltraATA specification.

Among other things, the Chipset also partially sets something known as the Cacheable Memory Area.  The cacheable memory area is the maximum amount of system RAM installed on the motherboard that will be 'cached.'   The benefit of caching memory is primarily performance, if you are making use of memory that is entirely cached by the Level 2 Cache subsystem on your motherboard then performance is at its peak.  One you step outside of the cached memory area your system must go directly to the system memory to fetch data instead of using the L2 cache as a middle-man (much like asking someone next to you for an answer vs asking someone across the room).  The cacheable memory area is entirely dependent on three things: the chipset, the size of the L2 cache, and the size of the Tag RAM (the latter two terms are defined and explored in greater depth in the AnandTech RAM Guide).  The cacheable memory area on all Super7 boards reviewed equipped with 512KB of L2 cache (based on the VIA MVP3 chipset) was 128MB, those based on the same chipset but equipped with 1MB of L2 cache was 256MB, double the original figure.  

When dealing with motherboards based on the ALi Aladdin V chipset things are made a bit more complex, the current revision of the chipset found on the only Aladdin V board that made it in time for the comparison (Iwill XA100) featured 512KB of L2 cache with a 128MB cacheable memory area.  While this number may change with Aladdin V motherboards to come, 128MB is the base cacheable memory area to expect from all Super7 motherboards, a limit which is more than enough for most users. 

The Socket-7 AGP arena is a bit more complex (yep, it gets worse).  The VIA VP3 chipset, although on paper  supports a full 512MB cacheable memory area, when placed on a motherboard with 1MB of L2 cache it will cache a full 256MB, naturally boards equipped with 512KB will cache half that amount, or 128MB. 

The SiS 5591 chipset, originally thought to be the World's First Super7 Chipset, actually a Socket-7 AGP Chipset with unofficial support for the 90MHz Front Side Bus speed, features a 128MB cacheable memory area when found on motherboards equipped with 512KB of L2 cache, the limit is doubled to 256MB when you pair it up with a board featuring 1MB of L2 cache.   

Back to the Super7 end of things, the two competitors there, VIA Technologies and Acer Labs Inc., both have chipsets that are pretty much equal in terms of performance.  Although the ALi Aladdin V does feature an integrated 16K x 10-bit Tag RAM and 16K x 2 L2 Cache SRAM (a feature which decreases cost and increases performance), the scale is tilted in favor of VIA by the MVP3's ability to run the SDRAM (Memory) Clock at the same speed as the AGP Clock, in theory allowing you to avoid shelling out the extra cash for PC100 SDRAM just so you can take advantage of the 100MHz FSB.  If neither of those features impress you, then simply aim for the motherboard with the best feature-set for your needs.

You must keep in mind that the intended goal of the Super7 platform was to combat Intel on the low end, with the "low end" in this case being the Intel Celeron Processor.   Because of this fact, many motherboard manufacturers saw no need for a "super" Super7 motherboard to be produced, eliminating many desires to produce a motherboard with a spacious layout.  Which is why, you will notice a considerable amount of cramped Baby-AT Super7 motherboards, and boards with 3 or 4 PCI slots in order to conserve space on the Printed Circuit Board (PCB) and in turn driving the cost down even lower.  This seems to be overly present in the MVP3 motherboard market, with the majority of Aladdin V motherboards available in ATX form factor models.  The Socket-7 AGP market, doesn't really have this problem as Socket-7 AGP motherboards based on the VIA VP3 chipset for example, were intended to be fierce competitors of the Pentium MMX/Pentium II before the time of the Celeron. 

The ability of the MVP3 chipset to run the SDRAM Clock at the speed of the AGP Clock, although a very useful feature, adds to the complexity of the jumper setup and configuration on MVP3 based motherboards.  Aladdin V based boards don't seem to have the problem of a complex jumper setup since they are essentially Socket-7 AGP boards with a stable 100MHz FSB setting.  If jumpers are as intimidating to you as they were when I first started building systems you may want to consider a board that uses Dip Switches or one that has a fairly easy to follow User's Manual/Jumper Configuration. 

In order to make room for more Memory Expansion slots some manufacturers gave up the excellent placement of the CPU Socket on their ATX boards, shifting the socket to the south by a few inches - resulting in a potential cooling problem for overclocked processors.

Make sure that the Socket-7 board you are looking at has enough expansion slots to accommodate your needs.  The growing problem of running out of PCI slots is even more present in the Super7 world, as the boards get smaller and smaller in order to save cost, the number of expansion slots also decreases.  Another issue that hasn't been much of a problem until now is the fact that manufacturers are placing the CPU Socket (on AT motherboards) in the way of the PCI slots, therefore preventing full length PCI cards (such as Voodoo² boards) from populating those slots.  In order for the K6-2 to truly be a threat to the Pentium II, although officially considered a "Celeron-killer" it requires the presence of a Voodoo2 board and benefits greatly by the presence of two such cards running in Scan Line Interleave mode for a performance boost.  If your motherboard doesn't have room for a full length card, you can pretty much forget about playing games on your new system, unless you plan on shelling out the heavy cash for a single board SLI AGP Voodoo2, in which case you're better off going for a new case/ATX Super7 board combo. 

One positive point about the layout issue with newer Socket-7 AGP/Super7 motherboards is that unlike their Slot-based competitors, they don't require all that much space inside of the case due to the fairly square design of the CPU Socket vs the long Single Edge Connector (SEC) on Slot-1 motherboards.  Are we beginning to regret the move to Slot-1?  Maybe...maybe not...

Other Unique Features

With BX motherboards there were considerable amounts of unique features present on motherboards, while you won't see any SB-Link ports on Socket-7 AGP/Super7 motherboards there are still a number of other features you will want to look for once you narrow your choices down to a select few motherboards. 

After eliminating the layout factors you may want to look for things such as single jumper configurations for either  the clock speed or the core voltage or both.  Some motherboards offer keyboard power-on functions which allow you to take full advantage of the ATX power supply by turning on your computer using a quick combination of keystrokes. 

The presence of "in-between" voltage steppings such as those between 2.2v and 2.5v and those between 2.8v and 3.5v are also features you may want to look for as they can help increase stability when overclocking voltage-sensitive processors such as the K6-2 and even the Pentium MMX and original K6 for that matter. 

Drivers packaged with the motherboard itself will help save you a few minutes of net-surfing to download the latest Bus Master and AGP VxD's, and naturally nothing can be of more help that a well written User's Manual and any other written documentation that may be provided by the manufacturer. 

First of all, with Socket-7 AGP and Super7 systems the most effective way to overclock your processor beyond the specification set forth by the manufacturer is by increasing what has become known as the Front Side Bus frequency or FSB speed.  The Front Side Bus speed is the frequency at which the Level 2 Cache, and Memory Subsystem (under normal conditions) operate at.  The rest of the components in your system, for the most part, derive their speed from that of the FSB.  For example, by multiplying the FSB by the clock multiplier you set on your motherboard you achieve the internal operating speed of your CPU.  By multiplying the FSB by the PCI clock divider set by your motherboard (usually 1/2 or 1/3) you will achieve the speed of the PCI bus.  Therefore by increasing the FSB you will have effectively overclocked your system.  Socket-7 AGP motherboards were never meant to support the 100MHz FSB and therefore only support the 1/2 PCI clock divider, meaning that running the at the 75/83MHz FSB speeds will result in running your PCI bus in excess of 13% out of the specified limit of 33MHz.  This could cause problems with some PCI devices, which is why Super7 motherboards feature a new PCI clock divider of 1/3 which keep the PCI bus frequency as close to 33MHz as possible (100MHz FSB * 1/3 = 33.3MHz). 

With that settled, let's move on to which processors overclock and how far you can push them:

AMD K6 166/200/233

The original K6 series were not the world's best overclockers, on a true Super7 motherboard you should have no problem running any of these chips at the 100MHz FSB with a 2x clock multiplier (200MHz).  Doing so will give you a nice 10% performance boost over a K6 clocked using a  66MHz FSB with a 3x clock multiplier (200MHz) due to the fact that the L2 cache operates at a much higher frequency with the 100MHz FSB.  The 233 can make it up to 250MHz reliably only if you increase the core voltage from 3.2v to approximately 3.4v, and in doing so you must increase the cooling of the processor as well as the system as a whole.  For Socket-7 AGP motherboards the 83MHz FSB (a rare setting on VIA VP3 boards) will probably be your best bet for the maximum performance, however if you happen to have a K6-233 and a Super7 motherboard then by all means try running it at 100 x 2.5...if not you can always stick to 100 x 2.0 which is sill faster than the 233MHz setting with a 66MHz FSB frequency. 

AMD K6 266/300

The next generation K6 chips boasted a lower core voltage setting, resulting in decreased amounts of heat production.  Both the 266MHz and 300MHz K6 parts seem to graciously accept the 100MHz FSB , with 100 x 3.0 as the upper limit on both of the chips (some 300's will make it up to 100 x 3.5 using a 2.3 - 2.4v core voltage setting).  Using the 66MHz FSB on a standard Socket-7 AGP motherboard you can easily push the 266 up to 300 and the 300 up to 333 without too many problems, although you're better off using a higher FSB frequency if you are looking to gain the most performance increase out of your overclocking. 

AMD K6-2 266/300/333

AMD's K6-2 is the topic of many discussions on-line these days, as any chip with this much potential should be.  One of the topics brought up has been the fact that the 266MHz K6-2 is rated for use with the 66MHz FSB, while the 300MHz part was intended for use with the 100MHz FSB.  The K6-2 266 doesn't seem to have any problems running at 100 x 3.0 making it virtually identical to the more expensive K6-2 300 except for the fact that the 300MHz unit has more of a chance of working at 350MHz.  If you only plan on running your system at 300MHz, and don't mind doing a bit of overclocking, save yourself some money and pick up the 266MHz K6-2, pop it in a Super7 board and enjoy some amazing performance at 300MHz.  The K6-2 can be used in older Socket-7 AGP motherboards as long as they support the required 2.2v core voltage (in some cases 2.1v has been known to work), however you won't be receiving the full performance benefits of your chip since you won't be running it at the 100MHz FSB.   The 300MHz chip will make it up to 315MHz (90MHz x 3.5) however 100 x 3.0 is still a faster setting, once again, due to the increased FSB frequency. 

The next chip in the K6-2 processor family will be the unique 333MHz part.  What makes the 333MHz part unique is that it is rated for use not with the 66MHz FSB, not even the 100MHz FSB, rather the 95MHz FSB using a 3.5x clock multiplier.  Since the 95MHz setting is not standard it requires a specially modified motherboard to run within specification on, however most users will be pleased with running their 333MHz chips at 350MHz using the 100MHz FSB.  You'll definitely hear more about this chip shortly when AnandTech takes an even closer look at the AMD K6-2.

Cyrix 6x86MX

The 6x86MX seems to be a no-go at the 100MHz FSB, if you plan on using the Cyrix processor on a motherboard you're better off sticking to a decent Socket-7 AGP motherboard or shelling out the extra cash for a K6-2 and pairing that up with a Super7 motherboard.  The new M-II from Cyrix may prove otherwise, but for now, the 6x86MX doesn't seem to hold that much of an advantage if any over the competition in the Socket-7 AGP world and definitely falls in last place in the Super7 market.

Intel Pentium MMX

Don't think AMD users get to have all of the fun with Socket-7 AGP and Super7 motherboards.  The Pentium MMX is a great processor, especially for use with the 100MHz FSB.  If you're looking for ways to squeeze more performance out of your aging Pentium MMX processor, toss it in a Super7 motherboard and enjoy the same 10% increase in performance with the 100MHz FSB once thought to be only reserved for Super7 processor owners.  The Pentium MMX 233 is known for being a wonderful overclocker, and by upping the voltage from 2.8v to a dangerously high 3.4 - 3.5v you shouldn't have a problem getting some experience with the Pentium MMX at 300MHz using the 100MHz FSB although running at that setting for extended periods of time isn't recommended.  The sweet spot for the Pentium MMX 200/233, due to Intel's incredibly high yields is 250MHz (100 x 2.5) and you will be more than pleased with the performance this processor can give you.

What does the future hold for the Socket-7 market?   The first signs of new overclocking possibilities have appeared, and they have arrived in the form of the 112MHz FSB.  A setting present on most BX motherboards is now appearing on Super7 motherboards, while the first generation of 112MHz capable Super7 boards are still a bit flaky expect to see much more of this setting in the future...after that, who knows what could be next to pop up, 125MHz...133MHz?  ...and beyond?   Looks like there could be more left in the Socket-7 market than we originally thought.

Search AnandTech's Mainboard Reviews for Reviews of all of the motherboards mentioned in this article