Intel unveils Bay Trail tablet SoC: Is superb performance and battery life enough?

At IDF 2013, Intel has finally fully unveiled Bay Trail, the tablet SoC that replaces Clover Trail. Bay Trail will come to Android and Windows 8.1 tablets this fall, and the initial benchmarks (carried out by third parties) look very strong indeed. CPU-wise, Bay Trail outperforms the entire ARM stable, including Cortex-A15 and Qualcomm's latest efforts, and on par with AMD's Jaguar-based Kabini, while consuming much less power. GPU-wise, Bay Trail is more middle of the road, with benchmark scores that compare to the iPad 4, but falling behind Tegra 4 and Snapdragon 800 by some margin (20%+). Overall, Intel seems to have finally produced an Atom part that can compete in both terms of power consumption and performance. The big question now is whether Bay Trail can secure a big product win: After all, without a beautiful and desirable product that can compete with the iPad and Nexus, Bay Trail doesn't stand a chance.

Bay Trail, at its most basic, is a brand new mobile SoC with up to four Silvermont CPU cores (no Hyper-Threading) and the HD 4000 graphics found in Ivy Bridge. Silvermont is a new out-of-order CPU architecture that's around three times faster than its predecessor, Saltwell. In Bay Trail, rather than the 16 cores found in Ivy Bridge's HD 4000 GPU, you only get four -- a significant and massively needed boost from the single-core PowerVR SGX GPU in Clover Trail, but by no means game-changing. These cores are DirectX 11 and Open GL ES 3.0 compatible. The GPU basically means that Bay Trail can run Android and Windows 8.1 and tablet-oriented games without issue, but it won't be playing Crysis any time soon. The CPU operates at speeds of between 1.3 and 1.5GHz (stock) and 2.4GHz (Turbo), and the GPU can clock up to 688MHz.

In addition to the new CPU and GPU, Bay Trail has dedicated hardware for video encode (H.264, MPEG-2) and decode (H.264, VP8, MPEG-2, etc.), and on the dual-channel models (Atom part numbers without the "D" designation) you get a heady 17.1GB/sec memory bandwidth to LPDDR3 RAM. Dual-channel models will be capable of resolutions up to 2560x1600, while lower-end models will only support 1920x1200 and lower. On the storage side of things, SDIO, SD card, and eMMC are supported, while for expansion USB 3.0 is supported.

Bay Trail performance

Without a doubt, the most important factors that will dictate whether Bay Trail stands a chance of success are performance and power consumption. Where Medfield and Clover Trail earnt Intel a space at the table, forcing device makers to take the chip giant seriously, Bay Trail needs to actually be as good as or better than the latest ultra-mobile chips from Qualcomm, Samsung, and AMD.

Benchmarks from sites such as Anandtech(Opens in a new window) and PC Mag(Opens in a new window) paint a very rosy picture for Bay Trail's CPU, which is best-in-class amongst other ultra-mobile chips, but the GPU is middle-of-the-pack. The chart below gives you a good idea of Silvermont's impressive performance under Windows:

Managing half the score of an Ivy Bridge CPU is really quite impressive. In single-threaded integer workloads the difference is even smaller.

But GPU-wise, though the HD 4000-derived core is more than four times faster than Clover Trail, it's still slower than AMD's Brazos. As Anandtech notes, though, this mid-range performance is enough that Bay Trail can run Team Fortress 2 at 1366x768 under Windows 8.1.

On the Android side of the equation, Intel's Bay Trail FFRD (form factor reference design) stomps all over the Nvidia Shield (Tegra 4/Cortex-A15) and the Nexus 10 (Snapdragon 800) in almost every test imaginable -- and once some bugs are ironed out in Intel's build of Android 4.2.2, Bay Trail's dominance should be cemented.

For the GPU, Bay Trail is slightly ahead of Snapdragon 600 (Adreno 320), but a good 30% behind the Snapdragon 800 (Adreno 330) and Tegra 4. Bay Trail's GPU should be more than good enough for current Android apps and games -- but it's certainly not best-in-class.

Bay Trail power consumption

The power consumption figures for Bay Trail look very strong. The impression from those who have played with Intel's FFRD is that Bay Trail's CPU consumes between 1W and 2.5W under load, which is comparable to Krait and other ultra-mobile CPU cores. If you factor the GPU into the equation, the SoC's total TDP seems to be around 6-7W -- again, just fine for a tablet form factor. It's not clear how Bay Trail does versus ARM (Krait, Cortex-A15, Swift) in idle power consumption, and we'll have to wait for some extended hands-on time before that can be sussed out. In general, though, all signs point to Bay Trail being competitive with ARM on power consumption/battery life.

Can Bay Trail succeed in the tablet space?

All in all, Bay Trail looks like a very solid successor to Clover Trail. If you end up with a Bay Trail tablet this Christmas, you won't be disappointed by its performance or battery life. Unfortunately, though, when it comes to devices, the SoC is really just a small part of the equation: Without the rest of the package -- the screen, the build quality, the app ecosystem -- the SoC is meaningless.

By all accounts, you can expect a lot of Windows 8.1 tablets to be powered by Bay Trail this fall. These devices will be cheap (hopefully $200-$500) and run the full library of x86/Win32 Desktop apps. With a Bluetooth mouse and keyboard, these devices will probably be perfect for media consumption and working in Office. You will still be hindered by Metro's weak ecosystem, though.

Android is a slightly more difficult proposition. Here Intel will be competing against the incumbents: Apple, Google, Samsung, and Qualcomm. For Bay Trail to succeed, it will need to more than merely offer comparable performance and battery life; it will need to provide proactive reasons for device makers and consumers to opt for the new-and-unknown Bay Trail, rather than a tried-and-tested iPad or Galaxy Note. Bay Trail will need to be significantly better in one or more arenas to drive a wedge between consumers and their current fondleslab. Intel clearly has an exciting product in the form of Bay Trail, and it's also a good indicator that Merrifield (the dual-core smartphone variant) will be potent, too. It now comes down to whether Intel can get the device wins, positive press, and consumer mindshare that will will transfer Bay Trail from impressive benchmarks to real-world commercial success.