Before the $399 iPad 2, before the $199 Kindle Fire, there was the $399 Eee Pad Transformer from ASUS. Like nearly all first attempts in the tablet space, the original Transformer wasn't perfect, but it was quite possibly the best try outside of Apple at the time. And unlike most of the Android competition at the time, it was priced sensibly at launch.

The $499 Eee Pad Transformer Prime showed up several months later, but not as a true successor but rather an upstream member of the family. Combining Tegra 3, an improved display and a much thinner chassis, the Prime once again took the crown as the best Android tablet on the market.

ASUS hasn't lost sight of its focus on cost however. At CES this year it announced a $250 7-inch Tegra 3 tablet, and today we get the first true successor to the original Eee Pad Transformer: the Transformer Pad 300. Priced at $379 for a 16GB WiFi version and $399 for the 32GB model, the Transformer Pad sheds the Eee label but keeps the spirit of the original Transformer. The Eee brand that launched with netbooks back in 2007 is clearly on its way out as the last of the netbooks will ship this year.

The Transformer Pad 300

The Transformer Pad 300 is more Prime than original. Similar to the original iPad or iPhone, ASUS' first Transformer had a unique ID that never really ended up being reused other than the basic dimensions.

The 300 is thinner and lighter than its predecessor, although it's obviously thicker and heavier than the Prime:

ASUS Tablet Specification Comparison
	ASUS Eee Pad Transformer	ASUS Transformer Pad 300 Series	ASUS Eee Pad Transformer Prime	ASUS Transformer Pad Infinity
Dimensions	271mm x 175mm x 12.95mm	263 x 180.8 x 9.9mm	263 x 180.8 x 8.3mm	241.2 x 185.7 x 8.5mm
Chassis	Plastic	Plastic	Aluminum	Aluminum
Display	10.1-inch 1280 x 800	10.1-inch 1280 x 800 IPS	10.1-inch 1280 x 800 Super IPS+	10.1-inch 1920 x 1200 Super IPS+
Weight	675g	635g	586g	586g
Processor	1GHz NVIDIA Tegra 2 (2 x Cortex A9)	NVIDIA Tegra 3 (T30L - 4 x Cortex A9)	1.3GHz NVIDIA Tegra 3 (T30 - 4 x Cortex A9)	3G/4G LTE - 1.5GHz Qualcomm Snapdragon S4 MSM8960 (2 x Krait) WiFi - 1.6GHz NVIDIA Tegra 3 T33 (T33 - 4 x Cortex A9)
Memory	1GB	1GB	1GB	1GB
Storage	16GB + microSD card	16GB/32GB + microSD slot	32GB/64GB + microSD slot	16GB - 64GB
Battery	24.4Whr	22Whr	25Whr	25Whr
Pricing	$399	$379/$399	$499/$599	?

The aluminum is gone and replaced by an all plastic back. The 300 doesn't feel cheap as a result and as you'd expect, feels a little less fragile as you're not as worried about scratching the aluminum.

From left to right: Transformer, TF Pad 300, TF Prime

ASUS Transformer Pad 300 (left) vs. ASUS Transformer Prime (right)

ASUS Transformer Pad 300 (left) vs. Apple iPad 2 (right)

The added thickness is noticeable compared to the Prime, but the 300 doesn't feel thick by any means. If anything, it's a bit more comfortable to hold than the Prime as a result of its added girth.

The weight is similarly noticeable, but once again I don't believe it puts the 300 in the category of too heavy. As this isn't a replacement for the Prime but rather a more affordable offering below it, these tradeoffs are fine.

The vibrate motor from the Transformer Prime is gone in the 300, when the volume is down the 300 is truly silent. Just like the Prime there's a single speaker on the back side of the 300 that puts out decent sound for a tablet. You're obviously limited by the size of the speaker but the 300 gets loud enough to play barely audible music while you're running a shower, if that's what you're looking for.

Just as with the Prime, there's a micro-HDMI connector on the Transformer Pad 300 for display mirroring:

The 300 will be available in three different colors: white, blue and red or ASUS has branded them - Royal Blue, Torch Red and Iceberg White. Only Royal Blue is available at launch (this week), with Torch Red and Iceberg white following in early June. 

The Dock

As this is still a Transformer, you can purchase an optional Transformer dock in a matching color for the 300:

The dock, as always, adds a QWERTY keyboard, trackpad, integrated 16Wh battery, full sized USB 2.0 port and SD card reader. The battery capacity is down from the Prime's dock (22Wh) and as a result extends battery life less than it does in the case of the Prime. I believe we're looking at a classic case of segmentation here, but even so the dock's integrated battery continues to be a brilliant part of the Transformer platform. Not only does it power the keyboard and touchpad but it also charges the 300's battery when docked.

Google has even added support for external batteries like the Transformer Pad's in Ice Cream Sandwich and you'll actually get two battery status indicators, in addition to an animation showing you how one is charging the other.

From left to right: Transformer dock, TF Pad 300 dock, TF Prime dock

The 300's dock is otherwise nearly identical to the Prime's dock, though it is modified to accommodate the thicker tablet. You can technically use the Prime in the 300's dock but the fit isn't quite secure due to the Prime's thinner form factor. Conversely, the 300 won't fit in the Prime's dock nor the original Transformer's dock - although the actual 40-pin dock connector remains unchanged. The price for the dock is still at $149, identical to what the Prime and original Transformer versions sold for.

The same limitations that came with those older docks apply here as well. With the tablet docked, the contraption is extremely back heavy and can tilt backwards if you're typing on your lap (or any non-flat surface) unless your hands are on the keyboard. The touchpad offers no real protection against accidental taps, although you can disable it via a function key on the keyboard. Although the docked tablet may look like a notebook, the construction isn't quite as solid as an inseparable unibody ultraportable design. The docked TF Pad may look like a Zenbook, but the Zenbook is always going to be more solid (and more expensive) for obvious reasons.

One nitpick I have about the TF Pad 300's dock is the return of the dangling USB port cover. ASUS had something similar on the first Transformer dock, but replaced it with a fully removable rubber stopped for the Prime. On the TF300T, it's back:

 

All of that said, the dock continues to be the best route for folks who want to do a ton of typing on their tablet - without giving up the portability and convenience of the tablet form factor. On trips you can choose to carry both pieces or just one if you don't plan on doing a lot of typing. At home you can quickly dock and undock the tablet as you shift between usage modes.

Updated Internals

Internally, the Transformer Pad 300 is once again more Prime than original Transformer. Whereas the original Transformer used an NVIDIA Tegra 2 SoC, the Prime and Transformer Pad 300 both use a quad-core (technically 4+1) NVIDIA Tegra 3 SoC. The two differ in their maximum clock speeds.

The Transformer Prime's SoC can run a single core at up to 1.4GHz, and 1.3GHz with more than one core active. The Tegra 3 in the Transformer Pad 300 on the other hand runs at a maximum of 1.3GHz (1 core active) or 1.2GHz otherwise. Note that this difference only exists in the maximum performance mode. Running the balanced power profile, the 300 like the Prime before it runs at a maximum of 1.2GHz regardless of number of active cores. In practice I saw the 300 typically top out at 1.1GHz and only rarely peak at 1.2GHz with the balanced power profile active (see: the three power profiles below).

The Prime's clocked its GPU somewhere around 500MHz, however the TF Pad 300's GPU runs around 400MHz.

NVIDIA Tegra 3
	Max CPU Clock	Max GPU Clock
NVIDIA Tegra 3 (T33)	1.6 - 1.7GHz	?
NVIDIA Tegra 3 (T30)	1.4GHz	~500MHz
NVIDIA Tegra 3 (T30L)	1.3GHz	~400MHz

It's clear that NVIDIA is employing a binning strategy with its Tegra 3 in order to make good use of parts of all yields. The T30 employed in the Transformer Prime ships at nominal clocks, while higher leakage parts (T33) will be used in the upcoming Transformer Pad Infinity that will run at up to 1.6 - 1.7GHz. The lower leakage/lower binning parts (T30L) get used by the Transformer Pad 300, and likely carry a slightly lower cost to ASUS as well.

One advantage the Transformer Pad 300 has internally compared to the TF Prime is its memory. While every single Transformer released thus far has shipped with 1GB of RAM, the 300 is the first to use 1.5V DDR3-667. The TF Prime used 1.5V DDR2-500 as far as I can tell. Don't expect any power savings from the new DRAM, but I believe this is a precursor to the Transformer Pad Infinity with its higher memory bandwidth demands.

I should also add that technically we're reviewing the ASUS Transformer Pad TF300T, the trailing T is for Tegra. ASUS has mentioned that it may introduce 3G and/or LTE equipped versions, the latter would presumably ship with Qualcomm's S4 SoC.

The Three Power Profiles

With the Transformer Prime, ASUS exposed the CPU governor settings for user control via three selectable power profiles. These profiles were originally named Normal, Balanced and Power Saving, however they have since been renamed Performance, Balanced and Power Saving. The behavior of the modes on the Transformer Pad 300 vs. the Prime is below:

ASUS Transformer Power Profile Settings
	TF Pad 300	TF Prime
Performance	Max 1C Speed: 1.3GHz Otherwise: 1.2GHz	Max 1C Speed: 1.4GHz Otherwise: 1.3GHz
Balanced	Max CPU Speed: 1.2GHz	Max CPU Speed: 1.2GHz
Power Saving	Max 1C/2C Speed: 1.0GHz Max 3C Speed: 760MHz Max 4C Speed: 620MHz	Max 1C/2C Speed: 1.0GHz Max 3C Speed: 760MHz Max 4C Speed: 620MHz

At a high level the main difference between the power profiles is the max CPU speed in performance mode. In Balanced and Power Saving modes these two appear to be equal. The reality is a bit more complex as the Prime tends to deliver lower performance in its Power Saving mode compared to the 300. There's also something funny going on with GPU performance in the Power Savign mode on the 300. With Vsync disabled, there's no performance difference between Power Saving, Balanced and Performance modes on the 300. With Vsync enabled however, we see a ~22% drop in GPU performance with Power Saving enabled.

In general, there's no real performance benefit to using Performance mode but a potentially tangible drop in CPU performance if you switch to power saving. The problem with the latter is that you may not save all that much power as max one or two core clocks aren't much lower than they are under Balanced mode (1.0GHz vs. 1.2GHz). We saw this echoed in our battery life results later on.

The Display

The Transformer Pad 300's display actually uses a panel that's closely related to what was used in the original Eee Pad Transformer and not the panel from the Prime. The most noticeable difference? The gap between the digitizer and the display itself. Similar to the original Transformer you can perceive the gap between the two, while the Prime's display narrowed that gap considerably. The comparison shot below exaggerates the effect a bit but it's present nonetheless:

The air gap between display and digitizer can result in more reflections, however in practice I found the TF Pad 300 not nearly as bad in this regard as the original Transformer.

 

The 300's panel is dimmer than the Prime's and came in a little dimmer than our original Transformer as well. Black levels are a smidge better than its predecessor, resulting in a competitive contrast ratio:

Color accuracy, at least for the primaries and secondaries, is on-par with the Prime. Grayscale accuracy is worse, but a little better than the iPad 2:

 

Gamut remains unchanged from the Prime at roughly 60% coverage of the sRGB space:

Subjectively the IPS panel looks just as good as the Prime, it's just dimmer. The max brightness of the 300 is more than enough for indoor use, it's only in outdoor use that it's limiting. In general I've found that you need to be able to push over 500 nits in order to produce a legible screen in bright sunlight.

Performance: A Prime Equal

With nearly identical specs to the Transformer Prime, the Transformer Pad 300 obviously performs quite similarly - particularly in the more software/CPU bound workloads:

The simulated gaming performance benchmarks in GLBench actually don't show much of a drop from the lower GPU frequency, which is a good thing if it means that actual gaming performance won't drop compared to the Prime:

The low level tests however, particularly those that are shader bound, do show a tangible gap in performance between T30 and T30L:

Notice the higher fill rate for the 300 compared to the Prime? I believe this is the result of the increase in memory bandwidth (2.67GB/s vs. 2.0GB/s, peak theoretical) thanks to the use of DDR3-667 in the 300.

GPS & WiFi Performance: No Problems Here

The all-aluminum construction of the Transformer Prime unfortunately resulted in WiFi performance degradation in certain situations compared to the original Transformer, and it pretty much ruined the tablet's GPS functionality. The latter got so bad that ASUS eventually removed GPS from the official spec sheet of the TF Prime and is now offering an external GPS dongle for those users who want better GPS performance.

The Transformer Pad 300 avoids all of these issues by being made completely out of plastic (and glass of course). WiFi performance is better than the Transformer Prime and more in line with the original Transformer as a result. Overall I'd say WiFi performance is pretty decent on the 300, whereas the Prime definitely has issues depending on what is between you and the AP:

WiFi Performance Comparison
Distance from AP	3 feet	20 feet (Different Room)	50 feet (Different Room/Floor)	80 feet (Different Room)
ASUS TF Prime (2.4GHz)	26.9 Mbps	9.85 Mbps	13.5 Mbps	2.20 Mbps
ASUS TF Pad 300 (2.4GHz)	26.5 Mbps	21.8 Mbps	20.7 Mbps	21.3 Mbps
ASUS Transformer (2.4GHz)	21.8 Mbps	17.6 Mbps	18.8 Mbps	15.0 Mbps
Apple iPad 2 (2.4GHz)	35.1 Mbps	29.9 Mbps	26.9 Mbps	10.6 Mbps
Apple iPad 3 (2.4GHz)	35.1 Mbps	29.9 Mbps	27.9 Mbps	9.98 Mbps
Apple iPad 2 (5GHz)	36.7 Mbps	36.7 Mbps	36.7 Mbps	11.9 Mbps
Apple iPad 3 (5GHz)	36.7 Mbps	36.7 Mbps	36.7 Mbps	11.7 Mbps

Whereas the Transformer Prime relied on two WiFi antennas and a dedicated GPS antenna, the 300 combines WiFi, BT and GPS into a single muxed antenna located to the left of the rear camera:

WiFi is still provided by the Azurewave AW-NH615, a rebranded Broadcom BCM4329 solution. ASUS tells me that depending on supply we may even see the original Transformer's Murata WiFi solution used in the 300.

GPS support is similarly driven by the same Broadcom BCM47511 used in the Transformer Prime, however this time we get much better performance. I hopped in a car (with a metal roof), drove to an area with clear sky visibility and tested each tablet resting on top of the center console, near where you'd find the gear selector in most cars. I created a WiFi hotspot on my phone to speed up ephemeris/almanac download speeds and relied on the tablets' internal GPS to determine my actual location. Here's what the GPS antenna is able to pick up on the Prime after 2 minutes:

ASUS Transformer Prime, GPS Status after 2 minutes

And here's what the Transformer Pad 300 sees after 18 seconds:

ASUS Transformer Pad 300, GPS Status after 18 seconds

Much better. Note that the SNR for the visibile satellites still isn't all that great. Indeed I don't know that I would recommend the 300 as an in-car GPS replacement, but its GPS performance is significantly better than the Prime. Just for comparison's sake, here's what the original Transformer saw after 18 seconds:

ASUS Eee Pad Transformer, GPS Status after 18 seconds

ASUS doesn't actually make mention of GPS support on its landing page for the Transformer Prime 300, and the WiFi-only iPads don't offer GPS as an option either. If you really want a good GPS solution you may want to consider either a smartphone or the LTE iPad.

Camera Quality

The Transformer Pad 300 comes with a 8MP rear facing camera (F2.2 aperture, 3264 x 2448 capture resolution) and a 1.2MP front facing camera (F2.4 aperture, 1280 x 960 capture resolution). The rear facing flash from the Prime is gone, although captured image quality appears to have gone up compared to the Prime in both low light and well lit conditions. The difference isn't always dramatic but it's clear ASUS did some ISP tweaking with the 300.

Taken with the Transformer Pad 300's rear facing camera

Images shot using the rear camera range in size from around 2.6MB to 4.5MB depending on the scene. Captures are very quick and the ICS camera UI feels very natural.

Video quality from the rear sensor isn't bad either, although it's best viewed at lower resolutions rather than the native 1080p output. The 300 captured using baseline H.264 at just under 16Mbps for the sample below:

While this low-light sample ended up with an average bitrate of around 8Mbps:

Note that neither capture was a consistent 30 fps. Average frame rate in the latter was around 16.7, while the former was much closer to ideal at 27.2 fps.

Battery Life

The Transformer Pad 300 ships with a 22Wh integrated, non-removable battery compared to the 25Wh unit in the Prime. The 12% decrease in battery capacity obviously reduces battery life compared to the Prime, however I believe the panel further reduces the life on a single charge.

The 300 either uses a less efficient panel, a less powerful backlight, or a combination of both as you need to drive the panel at around 70% of max brightness to hit our standard test luminance of 200 nits. The Prime, on the other hand, is capable of reaching 200 nits at 40%. The net result of these factors is a drop in battery life compared to the Prime, and approximately equivalent battery life to the original Transformer:

Note that these are older results for the first Transformer (not on ICS) as I haven't yet had the opportunity to re-run them. I'll be doing that as well as working on our new video playback test over the coming weeks.

I didn't see a huge impact from toggling power saving modes on battery life, although that does say more about the CPU load of our web browsing test than anything else. In general I saw spikes at up to 1.2GHz, but most of the time the Tegra 3 never reached beyond 1.1GHz and more often it operated in its lower frequency states.

The addition of the dock increased battery life by around 50%. Remember that the dock isn't perfectly power efficient, you lose some energy in the charging process and the dock itself consumes energy to power the keyboard and touchpad.

Charging

 

The new 18W charger (front) vs. the old 18W charger (back)

ASUS ships the Transformer Pad 300 with an 18W AC to USB wall adapter, although I noticed that the version that came with the 300 is actually a bit shorter than what I got with the Prime and original Transformer. Its power delivery capabilities remain unchanged however. By supplying 18W to the Transformer Pad, the power adapter can perform a complete charge of the 300's integrated 22Wh battery in a bit under 2.5 hours (remember charge current drops after all cells reach a certain voltage).

ASUS' latest Live Wallpaper, the water level indicates battery charge level

Usability and Final Words

Thus far I haven't really touched on the usability of the Transformer Pad 300 as a tablet, mostly because it's a topic I've addressed many times before in previous tablet reviews. I do believe a quick summary and update are necessary in this case however.

Fundamentally the Transformer Pad 300 doesn't change the iOS/Android balance, it's simply another great solution in the Android camp - at a lower price than the Transformer Prime. The fact that it doesn't carry any of the wireless issues of the Prime is an added bonus, particularly since it maintains many of the Prime's characteristics that we love (design, keyboard dock, performance, etc...).

As a device purely for browsing the web or sending emails, the 300 is easily in the same camp as the iPad 2. The user experience isn't as consistently smooth, but there are advantages that matter to some - such as the ability to support Flash and the ICS Gmail app.

As a tablet that needs to function as a netbook replacement, the Transformer Pad has an obvious advantage there as well. The Transformer dock remains the best way to turn a tablet into something you can type on for an extended period of time. While I don't believe that Android is any closer to a full blown notebook OS, as a netbook replacement I do believe the TF Pad 300 + dock is already there.

It's not all rosy unfortunately. The past few Tegra 3 updates to ICS for the Prime have decreased stability in my usage, and I saw a handful of app crashes on the 300 during my testing period. I didn't run into any showstoppers but the latest build of the OS on these devices doesn't seem quite as solid as the last Honeycomb build or even some of the earlier ICS builds. The good news is that ASUS and NVIDIA appear to be pushing out updates to these devices quite aggressively, which is unfortunately a rarity in the Android space.

Move outside of the core apps and Apple starts to gain a significant advantage, depending on the apps you're talking about of course. Then there's the UI experience, which for many continues to be a win on the iOS side. Although I still don't really believe that many folks cross-shop Android and iOS. The iOS experience ends up being more appliance-like while Google is building a mobile computing platform with Android. Both have their strengths/weaknesses.

I do appreciate that ASUS continues to deliver a mostly stock ICS experience with a few additions and a handful of useful preloaded apps (e.g. Polaris Office). The additions to ICS are all functional and ASUS tends to rely on its strengths as a great hardware manufacturer rather than gimmicky software to sell its Android tablets. I'd also like to applaud ASUS for offering sensible pricing on its NAND options with the Transformer Pad 300: $20 buys you another 16GB of storage. This is the direction I hope more tablet vendors go in the future.

At the end of the day the Transformer Pad 300 is a good successor to the original Eee Pad Transformer. If you want an upgrade to the original or are looking for an Android tablet at $399, the Transformer Pad is the one to get. If you find yourself looking at the Prime end of the market, then you'll want to wait until this summer when the Transformer Pad Infinity is expected to show up.

What I'm really hoping for is that ASUS is using its experience in building the Transformer lineup and bringing it to market as practice for the release of a truly perfect, x86-based Windows 8 tablet later this year. Give me the form factor of the ARM based Transformer Pad 300/Infinity (along with optional dock), but with the ability to run Windows 8 Pro and I think we may just have the perfect tablet for users who need a notebook for work but want the portability of a tablet.