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.
Facebook
Twitter
RSS
163 Comments
View All Comments
teiglin - Monday, December 24, 2012 - link
You don't have to wait for the coming years for Intel vs. ARM to replace Intel vs. AMD. The latter stopped being interesting when Bulldozer fell so short of Sandy Bridge. I was a long-time AMD fan, but they haven't released a chip I'd consider buying for myself since Deneb.kyuu - Tuesday, December 25, 2012 - link
I have to disagree. I'm far more interested in what AMD is going to bring to the x86 tablet space with Hondo than what Intel's doing, ATM.aspartame - Monday, December 24, 2012 - link
Intel cannot compete with ARM despite having the most advanced fabrication technology. Surely the new atom is somewhat more power efficient than the old Tegra 3, but it costs 3 times more.KitsuneKnight - Monday, December 24, 2012 - link
The 'new' Atom is also just a tweaked 5 year old Atom. What will be interesting is seeing how the next generation of Atoms compare against ARM's latest and greatest. Intel has proven that they can go blow for blow with ARM SoCs, despite just a couple years ago people claiming that x86 would never even be within several watts of any ARM.yyrkoon - Tuesday, December 25, 2012 - link
Technically speaking, Intel still can not approach ARM in power usage. It is all in the definition of "ARM". So, it is a matter of context.I think more appropriately people were saying that atom could never hope to approach ARM in the embedded market. Where they would be completely right. Unless you think an Atom based SoC could run under 100mw under full load.
Again . . .context.
KitsuneKnight - Tuesday, December 25, 2012 - link
People were talking about the Smartphone and Tablet spaces, not the ultra-tiny processors embedded into devices like SSDs. Intel doesn't really seem to want to compete in that space with their CPUs, as there's no profit to be made and no threat to their core business (they do occasionally compete with other products, but those aren't core products).The 'context' most people were talking about is the context that Intel is actually shown to be competitive in (at the very least against last gen devices). We'll see if they can appropriately pull the rest of their ecosystem together to lower the power consumption of the rest of the system, along with further reducing the power consumption of Atom while upping the performance.
yyrkoon - Tuesday, December 25, 2012 - link
This discussion started years ago in the embedded space where it should have stayed. Where ARM is still truly RISC in natureHowever, no less than a year ago( and probably more like 2 years ago ), several ARM low power desktop systems were demonstrated to use only 1-2w power consumption under full load. On YouTube no less. While Intel ( with atom ) was still fumbling around above 10w.
Having said that. "Competitive" is still a subjective term in this case.
At some point one has to realize, <this company> has <this> advantage over <another company>. But at what cost ? Which is partly why partners of ARM still exist in this market space.
jjj - Monday, December 24, 2012 - link
Funny how you compare 2 chips running 2 different OSes and you deem the results conclusive. How low can you go?karasaj - Monday, December 24, 2012 - link
Except if anything Windows RT will draw less power than Windows 8.Also, if you hook a resistor/volt meter etc. up to the CPU itself, the OS isn't going to do much.
Reikon - Monday, December 24, 2012 - link
Windows 8 and RT are essentially the same OS for different instruction sets with a few arbitrary feature differences unrelated to performance.