AMD’s Brazos vs. Atom Thermals, Revisited
by Jarred Walton on January 14, 2011 5:35 PM ESTAMD’s Brazos vs. Atom Thermals, Revisited
Last week, we met with AMD at their CES location to see some of their upcoming systems and laptops. While they’ve also recently released several new desktop GPUs, there wasn’t anything new to discuss in that area. The same applies to their desktop CPUs—we’re all waiting to see Llano and Bulldozer. So the focus at CES was understandably on Brazos, aka the “first APU” Vision C- and E-series processors.
We’ve been critical of some of the staged platform comparisons we’ve seen in the past—as Anand put it, the onus is on AMD in this case to provide a truly representative comparison between their new product and Intel’s competing offerings. After the demonstration of their Brazos netbooks on Thursday, AMD called us back and said they wanted to let us rerun the tests to make sure we accurately represented the two platforms. See, there was a slight snafu in the initial thermal imaging comparison. Specifically, AMD thought they put out a netbook with a C-50, but the test system was actually a C-30. So, we returned….
The reason for the mix-up was simple: they had both a C-30 and C-50 system from the same OEM, and they’re basically identical (one was dark blue and the other was light blue). Given that the two C-series parts are both 9W TDP, we didn’t expect much to change, and the new testing confirmed this. We did get some better images of both the top and bottom of the three test netbooks—Atom N550 vs. C-30 and C-50. Unfortunately, stupidity on my part resulted in the loss of said images (it’s a long story…), so all we have are the thermal shots from the keyboard area and screenshots showing CPU utilization during playback along with screen captures taken with FRAPS.
The above gallery shows essentially the same thing as our initial testing: Brazos using its GPU uses less power and runs cooler than Atom N550 doing the decoding in software. The difference between the C-30 and C-50 is pretty much non-existent, as expected. The testing environment was not conducive to doing any form of noise comparison, so while the N550 setup was clearly warmer we couldn’t say if it was quieter or not. Battery life is looking to roughly equal Atom, so that’s good to see. Now we’re waiting for final hardware to see if we can shed any more light on the situation, as well as running our full suite of tests.
We also took the opportunity to capture a video showing the 1080p playback comparison, as that’s part of the story. The video in question is Big Buck Bunny, an open movie demo created as part of the Peach movie project. (You can read more about it on their site, though it’s old enough now that if you haven’t heard of it already there’s not much to add. Suffice it to say, the lack of any licensing issues meant BBB was all over the CES floor, and I’m tired of the short now!) This particular version is a stereoscopic rendering, so instead of the normal 24FPS the frame rate is 48FPS according to FRAPS.
I believe during playback Arcsoft TotalMedia Theater 5 is skipping half the frames, as none of the netbooks come equipped with a 3D 120Hz panel. Does that actually matter? Not that we could tell—now that we’re home from CES, I ran the regular 24FPS version of Big Buck Bunny on a different dual-core N550 netbook, and frame rates still frequently dropped into the teens. Actually, it was worse than the netbook at AMD’s demonstration, but that’s probably more to do with lack of optimizations and some bloatware that came preinstalled; but I digress….
You can see during playback that the Atom N550 periodically stutters and drops below 48FPS—and more importantly, it’s far below 24FPS as well at times. In comparison, both the Vision C-30 and C-50 Brazos/Ontario chips manage a consistent 48FPS. The C-30 does flicker between 47 and 48FPS, but again, that may simply be an artifact of using a stereoscopic 3D video on a non-3D panel. Temperatures are in line with what we reported in our earlier coverage, and the two AMD netbooks are virtually identical. CPU utilization on the dual-core C-50 is lower by about half, as expected.
Once More, With Feeling
This is essentially the killer app of Brazos compared to Atom, and it’s important to keep things in perspective. These chips have a much better IGP than Atom, but at least on the nettop side of things the faster AMD E-350 isn’t miles ahead of Atom D510 in the CPU department. When we drop clock speeds down to 1.0GHz (dual-core C-50) from 1.6GHz (E-350) and compare that to the Atom N550 (1.5GHz)… well, 62.5% of the performance of E-350 compared to 90.4% of the performance of D510 means that in some tests the N550 will probably beat the C-50 for raw CPU potential. Yeah, that’s a concern for me. The GPU is the real difference, so naturally a video decoding test is the best-case scenario. I suspect C-50 will be underpowered for most 3D games, even if the DX11 GPU inside Brazos is fast enough—it will just be the AMD equivalent of Atom + NVIDIA ION, only without as many discrete chips.
We also have to consider performance of the next tier of CPUs and IGPs. Atom is the lowest of the low hanging fruit; we have much faster chips and IGPs from both AMD and Intel, and we don’t need to move up to current generation parts like 2nd Gen Core processors. Even the old Core 2 Duo CULV chips are a darn sight faster than Atom (2x-3x faster), and bad as GMA 4500MHD is, it could do an okay job at H.264 offload. It appears that the E-350 will end up delivering performance roughly equal to the old CULV chips (probably a bit slower, to be honest). That means it will also be around the same level as the Athlon II Neo K325, only with a better IGP and apparently improved power characteristics.
The biggest point in favor of Brazos isn't performance, though. It's going to be cost. If AMD can get partners to put out $400 netbooks (hopefully without Win7 Starter and with more than 1GB RAM), that will hopefully put the nail in the current iteration of Atom. We've seen the Brazos chips, and they're extremely small—smaller even than Atom—so pricing should be very compelling. AMD also doesn't appear concerned about protecting their more expensive mobile offerings (mostly because there aren't many), so they don't have to castrate Brazos in the same way Atom has been stagnant since the first N270 rolled out. Well equipped Brazos netbooks (and nettops) in the $500 range should also be a more elegant choice than Atom + ION/NG-ION, so again AMD looks set to win several matchups.
We’re working to get Brazos hardware in for testing as soon as possible, but it looks like the biggest beneficiaries will be users that want good H.264 decoding in a 10.1” form factor, or an alternative to ION. If you’re looking for the ultimate HTPC chip, we’ll have to investigate that area in further detail, as bitstreaming support and other features are still a question mark. Right now, Brazos is shaping up to be what we all wanted from Atom last year; whether that will be enough in 2011 remains to be seen.
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kc77 - Sunday, January 16, 2011 - link
Thanks for link to the E-350 which has benchmarks. The remarks about performance within this article are about C-50 and C-30 in this article. So seriously that's what I'm talking about. Thanks for helping though.Iketh - Sunday, January 16, 2011 - link
Hey buddy, I very much appreciated the summaries without benchmarks. The benchmarks will come later. If you don't like it, screw off, because I want to read them. They've done this many times before and have always backed themselves up later with data.ninjaquick - Tuesday, January 18, 2011 - link
I've rarely if ever seen anandtech's comments get so narrow to the side :Pkc77, dude, read the articles, read the benchmarks, read about the architecture... Atom is weak at best. Plus, if you are looking for Atom performance benchmarks then go to an article about that, no need to reiterate the same data several dozen times. Furthermore, I get the feeling Anandtech and its writers expect a level of knowledge from the readership. Apparently there are exceptions to the assumed knowledge levels. But by all means, challenge their posture and you will find that they are not lying or pulling things out of their.... hats.
Bobcat is good, but the power benefits from dropping the clock to 1GHz while also crippling the GPU is negligible, Jarred is talking about that. He is saying that Bobcat can and/or should compete against CULV, not Atom. That is his frustration. He figures a quad-core bobcat will still be crippled by low clockspeeds, and I agree with him on that.
kc77 - Tuesday, January 18, 2011 - link
"kc77, dude, read the articles, read the benchmarks, read about the architecture... Atom is weak at best. Plus, if you are looking for Atom performance benchmarks then go to an article about that, no need to reiterate the same data several dozen times."Did you not read what I was saying. I don't need benchmarks for Atom we know what that is already. As you said they are in other articles.
"Furthermore, I get the feeling Anandtech and its writers expect a level of knowledge from the readership. Apparently there are exceptions to the assumed knowledge levels. But by all means, challenge their posture and you will find that they are not lying or pulling things out of their.... hats."
Um this is about UNRELEASED hardware. Not hardware that can be bought. If it was purchasable then maybe it's readers would know about the hardware, which if that's the case Why come here? To read something I already know?
"Bobcat is good, but the power benefits from dropping the clock to 1GHz while also crippling the GPU is negligible, Jarred is talking about that."
You don't need to repeat what he said. I read that. However he made remarks on performance and didn't tell us anything in regards to what we ran and what score it got. Instead he provided insight that was half-technical without any becnhamrks to say why. ... That's the problem,
"He is saying that Bobcat can and/or should compete against CULV, not Atom. That is his frustration. "
Well maybe he should work for AMD and control their product lines. With all of this rambling it's going to come down to price. $100 regardless of performance matters in where these CPU's are marketed .
nitrousoxide - Friday, January 14, 2011 - link
And that's why I think choosing the right test suite (though I may not know what is a "right test suite") and counterpart for APU is important for such tests. But I really don't want to see APU being said "Oh, it sucks when you play Call of Pripyat and Farcry 2" or "It's incredibly slow in heavy H264 encoding".AnandThenMan - Friday, January 14, 2011 - link
I have no idea what you're rambling on about. But again another article that is negative towards AMD just for the sake of being negative. Why don't you just forget completely abut anything AMD and not write about them?Sorry but this is a horrible article.
nitrousoxide - Friday, January 14, 2011 - link
Come on Anand has always been positive towards AMD's Fusion APUs, just because Intel sucks with its Atoms and have been too conservative on refreshing the Atom product line for years.bjacobson - Friday, January 14, 2011 - link
huh? He seemed very kinda to AMD. What I saw was:"Atom just can't keep up"
"Brazos dips at places but that's probably drivers"
Why isn't a drivers issue with Atom? I've had a heck of a time getting the right decoding working on my gma500 but my 1.3ghz Atom with that GMA500 can decode 1080p24 video, or stream over wifi + decode 720p (don't have the bandwidth for the 1080p usually).
JarredWalton - Saturday, January 15, 2011 - link
GMA 500 was a horribly supported GPU, unfortunately. Not sure if the newer Z series will be better, but let's hope so. GMA 500 managed H.264 offload, but at least the system I tested was totally unstable (crashing several times per day). Last I looked, the drivers were still a year old.bjacobson - Saturday, January 15, 2011 - link
yes it was poorly managed, the crashing multiple times/day was because Acer shipped them with the wrong driver and drivers not installed correctly.Once I tracked down the correct one straight from Intel's site, and installed manually via "Upgrade Driver" (and specifically not running the intel setup.exe), it ran fine no more crashing.