The x86 Power Myth Busted: In-Depth Clover Trail Power Analysis
by Anand Lal Shimpi on December 24, 2012 5:00 PM ESTSunSpider 0.9.1
Now the fun stuff. Doing power profiles of our standard benchmarks gives us good insight into how well each vendor was able to balance peak performance and average power. In general it's ok to burn more power for a short amount of time as long as it means you'll get to sleep quicker. This was one of the fundamentals of the first transition to mobile from the early 2000s.
We already know that Intel completes SunSpider quicker thanks to its improved memory subsystem over the Cortex A9, but it also does so with much better average power (3.70W vs. 4.77W for this chart). A big part of the average power savings comes courtesy of what happens at the very tail end of this graph where the W510 is able to race to sleep quicker, and thus saves a good deal of power.
| JavaScript Performance | |||||||
| Time in ms (Lower is Better) | Kraken | SunSpider | RIA Bench Focus | ||||
| Acer W510 (Atom Z2760 1.8GHz) | 33220.9ms | 730.8ms | 3959ms | ||||
| Microsoft Surface (Tegra 3 1.3GHz) | 49595.5ms | 981.1ms | 5880ms | ||||
| Samsung ATIV Smart PC (Atom Z2760 1.8GHz) | 33406.0ms | 721.3ms | 3752ms | ||||
| Apple iPad 4 (A6X) | 19086.9ms | 834.7ms | - | ||||
| Google Nexus 10 (Exynos 5 Dual) | 11146.0ms | 1384.1ms | - | ||||
I also used SunSpider as an opportunity to validate the results from Intel's tablets with my own review samples. To generate this chart I measured power, every second, at the wall with both devices plugged in and with a fully charged battery. The resulting power consumption numbers include the efficiency loss at the AC adapter but the general curve shoud mimic the results above:
Note that the results do generally line up, although measuring at the battery gives more accurate results for the device and using the NI DAQ I was able to get better granularity on the power measurements.
Looking at CPU level power consumption we see a very even match between Atom and Tegra 3. Intel's advantage really comes from being able to complete the workload quicker (0.52W compared to 0.72W on average).
Once again we see a pretty significant difference in power consumption on the GPU rail between these two platforms.
Kraken
Mozilla's Kraken benchmark is a new addition to our js performance suite, and it's a beast. The test runs for much longer than SunSpider, but largely tells a similar story:
RIABench
RIABench's Focus Tests are on the other end of the spectrum, and take a matter of seconds to complete. What we get in turn is a more granular look at power consumption:
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powerarmour - Tuesday, December 25, 2012 - link
This is apples to oranges in some respects, the 5th companion core is disabled in Windows RT for Tegra 3, plus it's GPU is faster than the PowerVR core in the Clover Trail also.sonelone - Tuesday, December 25, 2012 - link
Once an A15 gets put in a Windows tablet, I would like to see an updated comparison.skiboysteve - Tuesday, December 25, 2012 - link
I'm a long time reader and and engineer at national instruments. I have used that usb-6259 and signalExpress many times. Very cool to see it on my favorite siteBeenthere - Tuesday, December 25, 2012 - link
AMD is the one who has been preaching the "User Experience" for years because their products in fact have been delivering a better User Experience when you run real apps and cut thru all the marketing B.S. and tainted benches that Intel spends fortunes on each year to manipulate hacks and consumers.It's no surprise that Intel is now trying to mislead the sheep on power consumption also, seeing as though AMD has had better power saving features in their CPU for years. Naturally Intel and certain hacks will proclaim this as an "Intel breakthrough" when in fact AMD has been leading the way in power reduction consumption in actual use - for years.
It's pretty easy to dupe the naive and gullible and Intel is really good at buying the media reporting they desire be it with ad dollars, invites to "special" events or other "perks" to gain a psychologically favorable interpretation of their latest marketing ruse-of-the-week.
The sheeple will buy into it all hook, line and sinker. If you're that technically challenged, you deserve to get fleeced.
puppies - Tuesday, December 25, 2012 - link
Don't hold back. Tell us how you really feel!Claiming AMD "leads the way" on power consumption and intel just follows is stupid.
Have you been in a coma since "I" series cpus were released. They beat AMDs CPUs on performance, power usage and performance per watt. I'm surprised you can see to type properly with your head that far up AMDs butt.
B3an - Friday, December 28, 2012 - link
It's Beenthere. He posts nothing but THE most stupid sh*t. He takes stupid to another level.I just hope he's mentally retarded in some way because if he's not, and is actually this stupid, then i feel embarrassed for him.
CeriseCogburn - Friday, January 25, 2013 - link
He is just the average amd fanboy. He is what all you'all ( u know whom ui r) have been for years here, he has just kept hanging on this past few months or half year instead of moving with the masses politically correct mindset change.Thus, we should all treat him as any other recently yet former and now scared to remain the same amd fanboy should be treated.
He was the majority here, he still is the majority here, he's just the last one with the guts to keep the charade going... perhaps forever. A nice landmark outlining the years of abuse the amd fanboys have delivered. Hopefully he will never change, a solid reminder and future melding point for the large amd fanboy base that will re-emerge ASAP when some opportunity presents.
yyrkoon - Tuesday, December 25, 2012 - link
Maybe on some level what you're saying is true but I find that both brands have their uses Depending on what a user wants / needs.Mostly the distinction I find is value vs reliability. Intel being slightly more reliable, while AMD offers more value. In this day and age, I think it is a mixed bag on which is more power efficient between the two.
It is hard to claim that AMD is more power efficient compared to Intel when AMD is offering 60w, 90w, and 120w desktop TDPs, where Intel is offering 35w, 45w, and 90w TDP variants. In the mobile arena, there is less distinction.
skiboysteve - Tuesday, December 25, 2012 - link
I'm a long time reader and I'm an engineer at national instruments. Very cool to see our stuff show up in an article!Tunnah - Tuesday, December 25, 2012 - link
I don't normally post comments, as I'm not smart enough to be able to figure into the usual conversations here, but I just had to post this to say this is an absolutely amazing article.I'm a high school drop out from the age of 15 with no further education, all my teaching has been done on my own accord, so what I know isn't indepth, it's just the broad strokes. I
I just wanted to let you know that your articles help me so much in my quest to educate myself, they're absolutely AMAZING, so easy to understand, and although I can only grasp the concepts of the things you're talking about, you propose them in a way where it doesn't go over my head.
I suppose this is just a drunken thank you message from a very grateful reader, who, without you, would be a lot more clueless about the things he really wants to understand :)