The x86 Power Myth Busted: In-Depth Clover Trail Power Analysis
by Anand Lal Shimpi on December 24, 2012 5:00 PM ESTFinal Words
Ultimately I don't know that this data really changes what we already knew about Clover Trail: it is a more power efficient platform than NVIDIA's Tegra 3. I summed up the power consumption advantage in the table below (I left out the GPU numbers since I'm not totally clear with what NVIDIA attaches to the GPU power rail on Tegra 3):
| Power Consumption Comparison | ||||||||
| Surface RT | W510 | Surface RT (CPU) | W510 (CPU) | |||||
| Idle | 3.182W | 2.474W | 70.2mW | 36.4mW | ||||
| Cold Boot | 5.358W | 3.280W | 800mW | 216mW | ||||
| SunSpider 0.9.1 | 4.775W | 3.704W | 722mW | 520mW | ||||
| Kraken | 4.738W | 3.582W | 829mW | 564mW | ||||
| RIABench | 3.962W | 3.294W | 379mW | 261mW | ||||
| WebXPRT | 4.617W | 3.225W | 663mW | 412mW | ||||
| TouchXPRT (Photo Enhance) | 4.789W | 3.793W | 913mW | 378mW | ||||
| GPU Workload | 5.395W | 3.656W | 1432mW | 488mW | ||||
Across the board Intel manages a huge advantage over NVIDIA's Tegra 3. Again, this shouldn't be a surprise. Intel's 32nm SoC process offers a big advantage over TSMC's 40nm G used for NVIDIA's Cortex A9 cores (the rest of the SoC is built on LP, the whole chip uses TSMC's 40nm LPG), and there are also the architectural advantages that Atom offers over ARM's Cortex A9. As we've mentioned in both our Medfield and Clover Trail reviews: the x86 power myth has been busted. I think it's very telling that Intel didn't show up with an iPad for this comparison, although I will be trying to replicate this setup on my own with an iPad 4 to see if I can't make it happen without breaking too many devices. We've also just now received the first Qualcomm Krait based Windows RT tablets, which will make another interesting comparison point going forward.
Keeping in mind that this isn't Intel's best foot forward either, the coming years ahead should provide for some entertaining competition. In less than a year Intel will be shipping its first 22nm Atom in tablets, while NVIDIA will quickly toss Tegra 3 aside in favor of the Cortex A15 based 28nm Wayne (Tegra 4?) SoC in the first half of next year. Beating up on Surface RT today may be fun for Intel, but next year won't be quite as easy. The big unknown in all of this is of course what happens when Core gets below 10W. Intel already demonstrated Haswell at 8W - it wouldn't be too far fetched to assume that Intel is gunning for Swift/Cortex A15 with a Core based SoC next year.
Here's where it really gets tricky: Intel built the better SoC, but Microsoft built the better device - and that device happens to use Tegra 3. The days of Intel simply building a chip and putting it out in the world are long gone. As it first discovered with Apple, only through a close relationship with the OEM can Intel really deliver a compelling product. When left to their own devices, the OEMs don't always seem to build competitive devices. Even despite Intel's significant involvement in Acer's W510, the tablet showed up with an unusable trackpad, underperforming WiFi and stability issues. Clover Trail has the CPU performance I want from a tablet today, but I want Apple, Google or Microsoft to use it. I do have hope that the other players will wake up and get better, but for next year I feel like the tune won't be any different. Intel needs design wins among the big three to really make an impact in the tablet space.
The good news is Microsoft is already engaged with Surface Pro. It's safe to bet that there will be a Haswell version coming as well. Now Intel just needs an iPad and a Nexus win.
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yyrkoon - Tuesday, December 25, 2012 - link
First, no one claimed ( at least seriously / sanely) that "ARM" would devour Intel. There *are* far more ARM based processors out there in the world than Intel. That is a simple fact. ARM has also existed for a long time, albeit not quite as long as Intel if I remember right.ARM sells far more processors. ARM has processors in just about any processor controlled type device you can think of ( and many you probably have not ). However, what is considered "ARM" may be a simple Cortex M0 processor that costs only a few US dollars. Used as a simple keyboard controller, or countless other possible uses. These devices are also RISC based, and are made to do specific purpose compute tasks while using very little power. Even less while in low power mode ( sleep ) with the ability to sometimes wake from an interrupt in as little as 1-2 cycles( we're talking microseconds here).
Lastly, if you wanted to compare processor revenue. You would have to compare profits from ARM, and ARM's partners who sell ARM based processors. You see, this is not an ARM vs Intel thing. This is the Intel vs the hoard that is ARM. "Thing". While also keeping in mind that costs can be considerably lower for ARM processors.
name99 - Tuesday, December 25, 2012 - link
Yes and no.You are right about Intel's disadvantages. But it's also worth remembering that ther are huge numbers of embedded devices out there based on some flavor of PPC (lots of game consoles, lots of network devices, lots of auto entertainment systems) or MIPS. And neither IBM nor MIPS was able to take that embedded advantage into the "branded" CPU space.
ARM is obviously different. They've managed to make their brand matter, and they are working hard on improvements (whereas both IBM and MIPS seem to be content to sell ever smaller dies of a design from the mid-nineties). But it would be unwise, IMHO, to assume too much advantage in ARM's plentiful very low-end sales.
yyrkoon - Tuesday, December 25, 2012 - link
"ARM" is winning in the context that more android devices have sold in the last few years, than x86 PC's have ever sold. At least according to an article I read a few months back.However that was not meant to be my point. My point was meant to say that ARM has been around a while, and will continue to be around a lot longer. While their profits are multii-entity, not single.
Personally, I like the fact that *now* Intel is paying attention.. It is good for the industry.
stimudent - Tuesday, December 25, 2012 - link
Also consider Intel's masterful use kickbacks to manufacturers and suppliers as well as threats to those who won't conform. That should help them too against ARM.mrdude - Tuesday, December 25, 2012 - link
and convincing these same OEMs to use Intel is going to be a tougher sell now. Apple and Samsung have no desire nor need for an Atom in a tablet when they've got their own SoCs. And superior SoCs, might I add.Mobile applications don't care what ISA they're running on, thus Intel loses the x86 compatibility point here. You're not going to run Photoshop on your smartphone and while it might work on your tablet, you're going to be pulling your hair out due to it's lackluster performance for productivity apps (see Anand's Clover Trail's review). If Intel restricts their x86 Atoms to Win8 devices, they're going to have a hard time selling these in any large quantity.
Then there's the issue of on-die GPU, which for tablets and smartphones is even more important than the CPU performance. That's one area where Intel still lags way behind the others. For mobile devices, gaming apps are the most popular. If Intel has great perf-per-watt and good CPU throughput but still lags woefully behind in GPU performance, the OEMs and consumers won't buy it. Asking a Clover Trail to game on a full HD display or even retina quality isn't going to work out well.
Price is what matters here above all else. In order for Intel to maintain their fab advantage they also require selling loads of processors at high margins. With huge competitors in the mobile space (Qualcomm just surpassed Intel in market cap) who sell these by the boatloads, Intel's going to have a very tough time of it.
It is great to see that the x86 power myth is busted, though. That 2-3% of die space dedicated to the x86 decoder doesn't seem to make too much of a difference. Now for the price and GPU portion...
Sahrin - Tuesday, December 25, 2012 - link
Intel doesn't compete with ARM, they compete with Qualcomm, Samsung, nVidia, etc. There is no ISA-level competition; ISA is irrelavant...that's the thesis of the article.Kidster3001 - Friday, January 4, 2013 - link
The ISA argument is exactly what people said about desktop PC's in the early 80's. "Everything is owned by IBM and Motorola. Intel can't win with this new x86 architecture thing." 10 years later?Same thing happened in Servers. "It's all owned by RISC now, x86 will never succeed in servers." 10 years later?
Then super-computers (HPC) "Intel doesn't stand a chance!" 10 years later?
Let's wait and see what mobile looks like in 5 or 10 years. History tells us that once Intel decides to seriously play the game, they figure out a way to win.
mavere - Monday, December 24, 2012 - link
I don't expect power efficiency here to compete well with the iPad, but I hope Intel gets there soon, if only to preempt any ideas Cupertino might have about moving the MBA line to ARM.Also, maybe Google's new Motorola subsidiary will do something with this. Samsung and Apple have their own chip designs, and MS doesn't really have room in its Surface + Surface Pro dichotomy for a slow(er) x86 part.
tipoo - Monday, December 24, 2012 - link
I'll be curious to see if Intel designs get such a power/performance lead that it gets to a point where Apple would be foolish not to switch over.Kevin G - Tuesday, December 25, 2012 - link
From a hardware stand point, Intel could get there. The problem with transitioning from ARM to x86 would be one of application compatibility. Apple has to maintain their app ecosystem and a platform change would be very costly. On the other hand, there would be a benefit to Apple solidifying their operating systems on one platform (and possibly merging iOS and OS X themselves).The other factor is that Apple is designing not only their own SoC's but also their own CPU cores. That is a major investment and Intel would have to have a seemingly overwhelming product for Apple to write those investments off.