Intel recently shared very granular power measurements of its Atom SoC and Nvidia's Tegra 3. If you previously believed ARM's architecture to be inherently more efficient, perhaps you underestimated the benefit of Intel's manufacturing and architecture.
Andrew Ku has been in the process of reviewing a couple of new tablets: Samsung's ATIV Smart PC 500T, with an Atom Z2760 inside, and Samsung's ATIV Tab, with Qualcomm's APQ8060A. I've been playing with Acer's Atom-powered Iconia W510, and my initial thoughts on that will go live soon.
One thing both Andrew and I are impressed with is that the Atom-based tablets, running full versions of Windows 8, compete readily with Microsoft's Tegra 3-powered Surface when it comes to battery life, and doubly so when you consider Acer's W510 only has a 26.6 Wh battery compared to the Surface's 31.5 Wh power source.
The sensitive stuff is blacked-out to protect the innocent
As far as performance goes, the Atom Z2760 (code-named Clover Trail) trades blows with Nvidia's Tegra 3 in our Geekbench numbers, but then completely blows it away in our Web browsing metrics. The fact that it's able to run x86-based apps fairly well is a clear benefit, too.
So, how do you get dramatically better performance in certain tests, and then competitive run time in those same workloads, all from a smaller battery? Answering that question would have been quite a challenge. But then we asked Intel to show us some of the advanced equipment in its own lab, which allows the company to take very granular measurements.
While we were up in Santa Clara last week, Intel presented us with data its performance analysis team had generated, showed us how it generated that information, letting us play with the test equipment ourselves, and discussed with us in great depth Clover Trail's strengths and weaknesses. Again, the following numbers come from Intel's team, not the Tom's Hardware lab. We did confirm that all displays were standardized to 200 cd/m2 (nits) using a Gossen Luminance meter, though, and power consumption is reported as the average over a 50 millisecond time slice. During the course of this piece, we'll break down Intel's numbers and compare them what we've done in our own offices, looking for connections.
| Idle: Microsoft Surface | ||||||
|---|---|---|---|---|---|---|
| Platform (W) | CPU (W) | GPU (W) | Memory (W) | Panel Backlight (W) | Everything Else (W) | |
| System Idle (Ideal): Windows 8 UI | 2.82 | 0.0038 | 0.21 | 0.25 | 0.98 | 1.38 |
| System Idle (Ideal): Desktop | 3.00 | 0.0047 | 0.21 | 0.25 | 1.11 | 1.42 |
| System Idle: Split Screen | 3.64 | 0.29 | 0.31 | 0.37 | 1.11 | 1.56 |
| Idle: Acer W510 | ||||||
|---|---|---|---|---|---|---|
| Platform (W) | CPU (W) | GPU (W) | Memory (W) | Panel Backlight (W) | Everything Else (W) | |
| System Idle (Ideal): Windows 8 UI | 2.47 | 0.02 | 0.11 | 0.29 | 0.84 | 1.22 |
| System Idle (Ideal): Desktop | 2.76 | 0.02 | 0.11 | 0.30 | 1.09 | 1.24 |
| System Idle: Split Screen | 3.37 | 0.18 | 0.24 | 0.36 | 1.14 | 1.45 |
For each tablet, Microsoft's Surface and Acer's W510, we're looking at power consumption on the Windows 8 UI, the Windows 8 Desktop, and a split-screen scenario, where a Windows 8 app is open on one side and the Desktop is open on the other. In this case, the Windows 8-style app is the primary screen and the Desktop functions as the sidebar.
The first column to pore over is the usage of each CPU. Tegra 3 delivers a very impressive idle processor draw of 0.0038 W in the Windows 8 UI interface, compared to the Atom's .02 W. But running in split-screen mode uses a lot more power. Tegra 3 jumps to .29 W, ahead of the Atom's .18 W.
Next up is the GPU. Now, we already know that the single-core PowerVR SGX545 in Intel's chip is quite a bit slower than Tegra 3 in 3D graphics. But at least in the 2D applications you run on both SoCs, the Atom's simpler graphics engine uses less power across the board.
Wired up to the requisite microsolder points.
The first hint of Intel's efficiency advantage comes from the memory column. At first glance, the Atom looks worse-off than Tegra. But remember that the Atom Z2760 sports two 32-bit memory controllers with LPDDR2-800 support, delivering up to 6.4 GB/s of bandwidth. The T30 found in most devices boasts a single-channel controller able to address DDR3-L at up to 1500 MT/s, yielding up to 6 GB/s. In theory, though, Intel's Atom has to do more work, suggesting its memory subsystem also operates more efficiently.
The rest of the platform includes the screen itself and panel electronics (like the LVDS transmitters), along with wireless radios, audio codecs, NAND, and anything else going on under the hood. Even in a scenario where Acer’s backlight eats up more power (operating in split screen mode), the rest of its platform is still 0.10 W more efficient.
But it's Christmas Eve, and sometimes there are more important things than running benchmarks and soldering wires to SoCs.
I'm thinking in the coming years, Intel vs ARM will become a more interesting battle than Intel vs AMD.
I was until I saw the numbers. Intel spent $8.4 billion in 2011 ($6.6 billion in 2010 and $5.7 billion in 2009) on R&D - http://www.intc.com/intelAR2011/business/research/ - while ARM isn't worth $1b. It may take a few years but Intel are seriously massive, they'll soon be the go to guys for mobile. Plus (according to rumours) with Haswell focusing on power saving, it could be a big leap forward.
I'm guessing the same thing. So far we've only seen it in a tablet (Nexus 10), and even that with its 10 inch tablet sized battery didn't last particularly long. ARM has the distribution advantage right now, but I think once Intel gets its foot in the door it will be the 900lb gorilla in this market as well.
Didn't Qualcomm alone overtake AMD as a chipmaker? The thing about ARM is that anyone can get a licence for the ISA and build a custom core around it, like Krait.
But it's Christmas Eve, and sometimes there are more important things than running benchmarks and soldering wires to SoCs.
Bit like comparing a 4x4 and a sports car in a muddy field.
We're already at quad-core ARM SoC's running at up to 1.7ghz. My understanding is that they won't be able to run too much faster anymore and will instead have to do more work per cycle. I think that's where Atom has the advantage in this case, which is why they can run slower but still accomplish the same amount of work with less power (but not faster).
If only this would translate into the Desktop/Laptop sector. We haven't had huge performance gains in the longest time. I miss the old days of Athlon 64...
Tegra 3 is junk and everybody knows it, bring on the Samsung Chromebook or a comparable tablet running an A15, and run Linux on them. Or rather than just waiting for Tom's to do it, check out the benchmarks on Phoronix that show the A15 eating the Atom for breakfast...
The advertised battery life on a Chromebook is very telling. It gets 6.5 hours of web browsing with a 30 watt-hour battery, so it's drawing 4.62W under that workload. This Atom tablet is drawing closer to 3.11W under an average web browsing workload and the Tegra 3 is drawing about 3.9W. We're looking at Snapdragon next and then A15, but I think everyone's going to be surprised once they look at the actual numbers when you're running apps other than Phoronix's benchmarks.
Atom Z530 (the "Z-class" Atom Phoronix tested).
http://browser.primatelabs.com/geekbench2/search?utf8=%E2%9C%93&q=z530
Atom D525 (the fastest netbook Atom Phoronix tested, which beats Exynos Dual in some applications)
http://browser.primatelabs.com/geekbench2/search?utf8=%E2%9C%93&q=d525
http://www.phoronix.com/scan.php?page=article&item=samsung_exynos5_dual&num=5
Atom Z2760
http://browser.primatelabs.com/geekbench2/search?utf8=%E2%9C%93&q=z2760
The Atom D525 had a TDP of 15W in 2010. The Atom Z2760 has the same performance with a TDP of
If the A15 is 2x the power consumption, is it consistently 2x as fast?