AMD has been curiously absent from the value netbook and nettop segments since Atom’s arrival nearly three years ago. These markets are highly profitable only for component vendors, as the OEMs that sell netbooks and nettops must survive on very slim margins in order to hit aggressive price points. It wasn’t too long ago that we were shocked by $699 desktop PCs, but to now be able to get a fully functioning portable PC with display at below $300 is impressive. In order for the profit equation to work out however, you can’t simply scale down a larger chip - you need an architecture targeted specifically at the type of very light workloads you expect to encounter in these segments. Underclocking and undervolting an architecture targeted at high end desktops or servers won’t cut it.

Generally a single microprocessor architecture can cover an order of magnitude of power envelopes. You can take an architecture from 10W - 100W using clock speed, voltage scaling and disabling features (e.g. cutting cache sizes). You can’t efficiently take a 100W architecture and scale it down to 1W. Intel realized this with Atom, and what resulted was a new architecture designed to span the 0.5W - 5W range. Given the constraints of the process (Atom was built at 45nm) and a desire to keep die size down to a minimum (and thus maximize profits), Intel went with a dual-issue in-order architecture reminiscent of the old Pentium - but with a modern twist.

AMD came to the same realization. For it to compete in these value markets, AMD couldn’t rely on its existing Phenom II derived architectures. The Phenom II and its relatives currently span a range of TDPs from 9W to 140W, and at the lower end of that spectrum we’re talking about some very low clock speeds and performance targets. Getting down to 1W was out of the question without a separate design.

What AMD came up with was a core called Bobcat, initially targeted for netbooks, notebooks, nettops and entry level desktops. Architecturally Bobcat is a significant step ahead of Atom: while still dual-issue, it features an out-of-order execution engine making it the Pentium Pro to Atom’s Pentium.

It isn’t just CPU architecture that AMD surpassed Atom with, the first incarnation of Bobcat is an integrated SoC with on-die DirectX 11 GPU. AMD calls this combination a Fusion APU (Accelerated Processing Unit) as it places both a CPU and GPU on a single die. The possible CPU/GPU combinations for Bobcat based APUs are listed in the table below:

AMD Brazos Lineup
APU Model Number of Bobcat Cores CPU Clock Speed GPU Number of GPU Cores GPU Clock Speed TDP
AMD E-350 2 1.6GHz Radeon HD 6310 80 500MHz 18W
AMD E-240 1 1.5GHz Radeon HD 6310 80 500MHz 18W
AMD C-50 2 1.0GHz Radeon HD 6250 80 280MHz 9W
AMD C-30 1 1.2GHz Radeon HD 6250 80 280MHz 9W

AMD avoided branding its first APUs, they’re simply the AMD E-series and C-series Fusion APUs. The emphasis isn’t on the CPU or the GPU in this case, just the company name and a model number.

AMD's E-350

CPU Specification Comparison
CPU Manufacturing Process Cores Transistor Count Die Size
AMD Zacate 40nm 2 ? 75 mm2
AMD Thuban 6C 45nm 6 904M 346mm2
AMD Deneb 4C 45nm 4 758M 258mm2
Intel Gulftown 6C 32nm 6 1.17B 240mm2
Intel Nehalem/Bloomfield 4C 45nm 4 731M 263mm2
Intel Sandy Bridge 4C 32nm 4 995M 216mm2
Intel Lynnfield 4C 45nm 4 774M 296mm2
Intel Clarkdale 2C 32nm 2 384M 81mm2
Intel Sandy Bridge 2C (GT1) 32nm 2 504M 131mm2
Intel Sandy Bridge 2C (GT2) 32nm 2 624M 149mm2

These APUs do need the aid of an additional chip - the Hudson Fusion Controller Hub (FCH). The FCH adds support for things like SATA, USB, Ethernet and Audio.The Hudson FCH is very tiny measuring approximately 4mm x 7mm for a total die size of around 28mm2.

The Hudson FCH

The combination of these Bobcat based APUs and the FCH is called the Brazos platform.

Late last year AMD invited me to spend several hours with a Brazos system at its brand new campus in Austin, TX. While the preview gave us some insight into what we could expect from Brazos, I didn’t have enough time to really dive in as much as I would’ve liked to.

Earlier this month, AMD officially launched Brazos with hardware expected sometime this quarter. For the past couple of weeks I’ve been testing a Brazos mini-ITX motherboard from MSI and today, it’s time to break the silence and share the results. They are quite good.

The Price: Around $100, The Motherboard: MSI's E350IA-E45


View All Comments

  • Matt310 - Friday, January 28, 2011 - link

    At home in my desktop machine I have a 4-lane PCI-x hardware RAID card with four 1.5TB drives configured in RAID 5 for speed hand fault tolerance. For a while now I've been wondering how the i/o performance of a good RAID card would fair if it was moved to a low-power (e.g. Atom- or Brazos-based) mini-ITX NAS system. I've been googling for a review of this setup but not been able to find anything conclusive.

    Think a lot of people would appreciate if you guys could give this a try and report on your findings!

    Thanks Anand!
  • msroadkill612 - Friday, February 04, 2011 - link

    Well you should know - dont the raid cards have their own smarts & put little work on the cpu?

    My guess is it would be a great unit for a dedicated server. In the old days, many dedicated servers kept their 486 pcS for a decade as they ran fine.

    a post above linked to a comparison of running pciE graphics cards at 1,4,8,16 lanes, & the difference between 4 x &16 by was slight. I imagine its the same with raid cards.
  • jjcrandall - Friday, January 28, 2011 - link

    Anand, I didn't see what hdd you used for the tests. It would be very interesting to see how this platform performed in some of the benchmarks with a ssd. I know pcmark & vantage productivity benches use hdd test's to a certain degree.

    This really shows either how poor netburst was as an architecture, or how good existing sub 10w designs are.
  • Shadowmaster625 - Friday, January 28, 2011 - link

    It seems like the E-350 was built for overclocking. Especially on the desktop or with any cooling solution that has an extra 10 Watts of thermal headroom. Sooner or later someone is going to release a mini-ITX board that can OC an E-350 up to 2.5GHz and beyond. Right? It's not like the new intel cpu where you cannot overclock it, right? Reply
  • bjacobson - Saturday, January 29, 2011 - link

    yeah I definitely want to overclock it!
    In a laptop when you've got an 8-10 hour battery life, if you know you're only going to need the laptop for 4 hours today, why not just crank up the speed? Great having that option.
  • Arnulf - Friday, January 28, 2011 - link

    "Unfortunately in modern titles that's not always enough to have a playable experience, but with older games you should be able to do more with Brazos than you ever could with Atom or even ION for that matter. The CPU/GPU balance in the E-350 is good enough that I feel like Llano could make for a pretty decent value gaming machine."

    Given that Zacate/Brazos performs at the level of 5+ years old midrange desktop CPU with midrange GPU and considering the quoted statement above it would be very interesting to see some actual performance data taken in titles that Zacate/Brazos *can* run at bearable FPS rates.

    You could look up your performance charts from 5 years ago, dig out the old titles and rerun the benchmarks with those titles on Zacate/Brazos. This should give people better idea what they can expect from this generation of APUs. Sub-20 FPS rates in modern titles at rather low resolution and with all details at minimum isn't exactly what people have their sights on when deciding whether to shell out money for their new toy. Comparison with other crappy graphics that is on par with 5 year old solutions may give AMD's platform some edge over competition from Intel's camp, but it utterly meaningless as nobody is planning to use it in such setting.

    Myself, I'd *love* to see some factual data from titles such as CoD2, DiRT, Doom3, etc. - the games you were referring to in the paragraph quoted above and all of which you already have reference benchmarks of (in order to have something to compare Zacate/Brazos against, without having t rerun all the benchmarks with old software titles). Such a benchmark with usable performance and enough eye candy will help put Zacate/Brazos' use in gaming setting into perspective, very much unlike those ~20 FPS tests you did above.

    These merely indicate that integrated graphics of today are still useless for gaming.
  • bjacobson - Saturday, January 29, 2011 - link

    Hm that's a good point. Likely I'd be playing a copy of UT2k4, perhaps quake 3 online, or some older online RTS. How do these fare at those games? Reply
  • cjs150 - Friday, January 28, 2011 - link

    Nice review.

    There is a passively cooled E-350 board coming out. The review convinces me that this will be the right choice for the HTPC for the main room.

    Why: TV already connected to an AV receiver so an E-350 system can use the HDMI connection to the AV receiver. E350 more than powerful for BluRay, fine for some light web surfing, ripping music. Maybe stick a TV tuner in as well and that is the main room sorted.

    I have no intention of playing modern games on it so lack of power is not a problem. I have a bigger PC in study to rip movies if it takes too long on the E350.

    But I also have an Atom based system. Again passively cooled. I use it as a server for the home network. It works just fine. It was cheap, ultra easy to build and just works. The fact that Atom is rubbish does not matter because as long as it can shift data round the network I need nothing more.

    So every CPU has a purpose, just with some we have to look hard
  • BernardP - Friday, January 28, 2011 - link

    AMD might score technical successes with its new lineup (Bobcat, llano, Bulldozer), but it will have trouble marketing them if only meaningless C Series, E Series, A series (Llano) and whatever Series (Bulldozer) are used.

    last time I looked, a C350 and E350 were Mercedes-Benz models, while CSeries is an upcoming Bombardier jet:

    In addition the numbers seem meaningless. Even intel's Core naming scheme is clearer than AMD's.

    AMD simply needs 3 distinct marketing names that the general public will understand for its 3 new product lines code names: Bobcat - Llano - Bulldozer. "Fusion" and "Vision" just don't cut it anymore, as they have already been used for years by AMD.

    One can easily see that there is a problem is the naming scheme when OEMs have to use the Zacate and Brazos code names to try to describe the product, like this example:
  • nitrousoxide - Friday, January 28, 2011 - link

    Yeah...the naming scheme ASUS and ACER use makes people mad when choosing laptops :) Reply

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