AMD’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.



View All Comments

  • mino - Saturday, January 15, 2011 - link

    Multithread my ***.

    While the browser might be multithreaded, the stuttering Flash video is STILL using a single core/thread.

    Atom needs HT to get any reasonable "benchmarketing" results.
    But you know what? Desktop experience is pretty much orthogonal from "throughput computing" performance Atom or Niagara provide.

    HT/SMT is _GREAT_ for throughput(i.e. server) while often giving NEGATIVE gain for UI/GUI desktop performance that relies on many simple single thread-ed tasks.

    It was that way back in the NetBurst days, then on Niagara, then on Atom and now on Nehalem/SNB.

    The single major benefit of HT on desktop is when having 1 physical core is hampering the scheduler. But that advantage is the wild card of the 2001, not 2011.
  • ninjaquick - Tuesday, January 18, 2011 - link

    You should watch out about calling a single threaded program that windows 7 throw onto multiple thread multi-threaded since it probably isn't, Reply
  • overzealot - Wednesday, January 19, 2011 - link

    OS's can't split threads. Nice try though! Reply
  • Shadowmaster625 - Wednesday, January 19, 2011 - link

    When you launch any program you are spawning multiple threads. Often there are more than 4. But most of them are short lived. In most cases, having 2 cores helps applications launch faster. But having more than two helps not a bit in most situations. I have a unique perspective on this since I have 2 machines that both have the same motherboard, hard drive, and RAM, and one is a E6600 and one is a Q6600, both clocked at 3.2GHz. The Q6600 is only noticably faster when you launch an "abnormal" number of applications simultaneously. For example, I have a script that opens 4 pdf's, 2 excel spreadsheets, 2 calc spreadsheets, 2 word docs, 2 swriter docs, a ppt file, an impress file, an mp3 in media player, an avi file in vlc, a quicktime video, a bmp in paint, a txt in notepad, a log in wordpad, and a few others i cant remember at the moment. Only in extreme cases like this is the quadcore faster than the dual core. Reply
  • overzealot - Thursday, January 20, 2011 - link

    Actually, whenever you launch a program you are creating 1 thread. It may then create new threads, or make system calls (which may create threads of their own). But, it certainly isn't always.
    Also, when describing an application as "multi-threaded", the usual emphasis is on concurrent execution of said threads.
    Threads created by system calls may execute concurrently, but the original application thread will wait for them to respond sequentially.
    Case in point - open notepad: 1 thread. Open a file in notepad - up to 20 threads. The original program is still a single thread, it just now makes requests to other threads inside the same process - this incurs less penalty than making requests to other processes. That's a benefit, but number of cores doesn't affect it.
    I do hope you didn't buy a quad core just to make apps load faster though. Mine gets plenty of it's workout from encoding and compiling, and a bit of action from games.
  • psiboy - Saturday, January 15, 2011 - link

    While Anandtech theorises Tom's Hardware has delivered.... go and read their comparisons.... Reply
  • H83 - Saturday, January 15, 2011 - link

    I have to say i´m disappointed by those results.

    I though the new CPUs would beat the crap out of the super crappy Atom but in many ways it´s just the same, it´s basically AMDs Atom version with a better IGP at a lower cost. AMD as to try harder to beat Intel in this game.

    By the way, can you tell when will Anandtech review Sansy Bridge mobile CPUs? They seem perfect for my next laptop with a very good performance and hopefully lower power requirements.
  • krumme - Saturday, January 15, 2011 - link

    So you think a cpu that is aprox 60% faster on real world usage, turning the Atom computer from unsusable to tolerable, on the same cost is disapointing.

    Well for the the 20 years i have followed the evolution there has not been a single cpu, - and nor will there for the foreseable future - be a cpu that will change how the market works.

    As of now every OEM and their brother is going for e350 for the simple reason that it does get the job done for 90% of the users, at a fraction of the cost of a core2/AMD whatever.

    There can be at least 800 pcx. on one wafer, that in the region of 6-7 usd per die, add packaging and shippihng - the marginal - marginal - cost is at most 4 usd here. And you have a marginal cost in the region of 11usd, probably a few usd more than the Atom. The result is already showing.

    People dont give a s..t about all kind idiotic benchmarks. The OEM dont care if its AMD or Intel anymore, as long as there is no complaints from the customers. Atom is the reason that people still know what a cpu is, because it simply is to slow even for women. The results is that bobcat will sell like hotcakes. At a selling price of fx. 40usd, that is a good business for AMD, as the fixed cost can be shared to next version and a broader portfolio. As the pincount is lower than Atom, there is no reason to beliewe it will no go to 300usd.
  • krumme - Saturday, January 15, 2011 - link

    But disagree how it should be interpreted.

    First of all thanx to Jarred for participating

    The funny thing is it seems we all know what to expect. Its the context that matters.

    Jarred says they are using bm that suits their readers. Thats right, but thats not the right choice. What is so brilliant about Johans server test, is that he test the cpu in scenarios where they will be used - server situations. Its very simple. He dont use test outside of the purpose of the cpu. The reviews of bobcat should reflect the same methology.

    There is absolutely no reason to test the bobcat in scenarios where it will not be used - or only in very rare situations. The wider consequences of doing so is forcing the manufaturas - here AMD - to produce 4 core bobcats with 1Mb l2 cache. The effect would be an idiotic waste of ressources. The customers should rather use the money on better screen, battery or ssd.

    For the ssd discussion the interesting thing about the atom is, that it can hardly use a 5400rpm hd, therefore the extra power of the e350 with a 7200rpm (or a very cheap-slow ssd) turns into real user experience.
  • Aone - Saturday, January 15, 2011 - link

    Quite a strange that neither AMD not the author didn't notice the difference between C-50 and C-30 because the former has two cores while the last only one core.

    And, BTW, C-Brazos has not only lower cpu frequency but gpu one also.
    How really he will stack up to Atom?

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