The x86 Power Myth Busted: In-Depth Clover Trail Power Analysis
by Anand Lal Shimpi on December 24, 2012 5:00 PM ESTPower During Boot
For the next test I measured power during a cold boot process. Here we're looking at power consumption from device off to hitting the Windows Start Screen:
Now we get our first glimpse of active power and there's a definite advantage here for Intel. Peak power consumption for the entire tablet tops out at just over 5W compared to 8W for Surface RT. Let's dig deeper to find what is responsible for the added power consumption:
The difference in average CPU power consumption is significant. Tegra 3 pulls around 1.29W on average compared to 0.48W for Atom. Atom also finishes the boot process quicker, which helps it get to sleep quicker and also contributes to improved power consumption.
GPU power is a big contributor as well with Tegra 3 averaging 0.80W and Atom pulling down 0.22W.
Launching Word 2013
As another simple test, I looked at power consumption while launching Microsoft Word 2013 on both platforms:
Here both tablets seemed to finish in about the same time but if you look at the power consumption graph you'll see that the W510 actually took a little bit longer. The difference wasn't great enough to really change the power profile: NVIDIA consumed 0.60W on average for its CPUs, while Intel pulled 0.48W on average:
Once again, there's a pretty stark difference on the GPU rail which makes me wonder if we're not looking at more than just GPU power here. Either that or Tegra 3's GPU implementation isn't all that power efficient compared to Imagination's. For the raw averages you're looking at 0.73W for NVIDIA compared to 0.23W for Intel.
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felixyang - Friday, December 28, 2012 - link
You get the keypoint.st.bone - Tuesday, December 25, 2012 - link
Now that's just out right ignorant on your comment, that's if you even took the time to read the articlejeffkibuule - Monday, December 24, 2012 - link
This kind of makes me shake my head as to why a year old SoC was used when Samsung was shipping Exynos 5250 and Qualcomm had APQ8064, heck nVidia has Tegra4 just waiting in the wings for a likely CES announcement (I know why, bad timing).My only hope is that in 2013, ARM and Atom SoCs can support 1080p displays, I don't think I can use anything less without wanting to poke my eyes out.
kyuu - Monday, December 24, 2012 - link
Agreed. This article mostly highlights what an out-of-date SoC Tegra3 is, and how bad it is without its companion core. Which is why its so perplexing that Microsoft went with the Tegra 3 for the Surface. I can only guess that Nvidia must be practically giving away Tegra3 nowadays, otherwise I have no idea why anyone would use it.I'm not sure it's a huge win for Intel that Clover Trail beats a mostly obsolete ARM SoC in power use with such an incredibly mediocre GPU.
A more interesting comparison would be between a current-gen Qualcomm chipset and/or Samsung's current-gen Exynos.
kyuu - Monday, December 24, 2012 - link
To clarify the second "paragraph", Clover Trail is the one with the mediocre GPU.lmcd - Tuesday, December 25, 2012 - link
They're both mediocre GPUs at this point. Didn't Adreno 225 keep pace with the T3 GPU?jeffkibuule - Tuesday, December 25, 2012 - link
The reasoning for going for Tegra 3 was pretty obvious. They needed a more finalized chip to develop Windows RT against and Tegra 3 was the only thing available. Relying on a faster class of SoCs in the Tegra 4, Snapdragon S4 Pro, or Exynos 5250 would mean delaying the Windows RT version of tablets by several months at least since I doubt development would have been done in time.lmcd - Tuesday, December 25, 2012 - link
S4 standard would've done better more likely. Clover Trail demo'ed how viable two cores was for W8, let alone W8 RTwsw1982 - Tuesday, December 25, 2012 - link
There is already the comparison between the medfield, krait, swift and Exynos 5250 on the android platform, isn't there? I think microsoft is the one to blame that you can only compare clover trails and tegra 3 on windows platform, LOLKrysto - Monday, December 24, 2012 - link
Intel will not have anything that even approaches next year's ARM SoC's GPU's anytime soon. And they can't match Cortex A15 in performance anytime soon either.