Gigabyte E350N-USB3 AMD Fusion APU motherboard review

Brazos, Fusion, APU - what is it all?

Schadenfreude

You know, it's nice when you catch a break or two, more so when you're considered very much the underdog. Chip company AMD caught a break when Intel announced that its stellar Sandy Bridge platform was compromised by a manufacturing issue that really should have been picked up during the usually extensive qualifying period. The flaw in the 6-series chipset, detailed here, looks set to cost Intel some $700m to put right. Worse still, Intel's many partners are still waiting before shipping Sandy Bridge-based laptops and PCs in volume.

The lack of Sandy Bridge shipments means that AMD has a small window of opportunity to flood the channel with its chipset and laptop technologies before Intel papers over the cracks by ramping up production of corrected silicon, though that appears to be diminishing as AMD's own next-gen desktop part, known as Llano, is yet to be seen in the wild.

But AMD undoubtedly wants to give Intel a good fight in all areas, and one such segment that it has identified is the low-power, low-cost notebook and desktop market. Bringing its GPU and CPU know-how together with the Fusion APU parts, the company wants you to consider them for the next budget build.

Brazos on the desktop

AMD breaks out the Brazos platform to wreak havoc on Intel's Atom ecosystem. Brazos is the name - the 'arm' inference noted - and it's an accumulation of AMD technologies that bring together, on one piece of silicon, the Bobcat CPU and Radeon HD 6000-series integrated graphics. These are supported by the Hudson chipset. Got that? Nope? Thought not.

Bobcat chip

The 40nm-based Bobcat CPU is a brand-new architecture from AMD, ostensibly designed for low-power compute. While dialled-down compared to its desktop counterparts, the out-of-order (read good) design is available in single- and dual-core guises, both of which are without any form of hyperthreading goodness, though.

Folk who need a really low-power chip will look toward the Ontario implementation, rated at 9W TDP, while those that strive for a bit more oomph will go for the Zacate model, plumbed with an 18W TDP

But it ain't that simple. You see, Ontario and Zacate codenames actually refer to the entire chip, including GPU, so you get a heck of a lot for your watts, compared to what AMD has offered in the past, anyway.

Ontario, then, is designed primarily for netbook-type computers, and it can be outfitted with either one or two Bobcat CPU cores. Give yourself a few more watts and the faster-clocked Zacate - up-to 1.6GHz vs. Ontario's 1GHz, also presented with either one or two cores - becomes available. Zacate, in particular, should give Intel's Atom a good kicking, you would think.

DX11 graphics

The CPU portion is the boring bit, if I may be so bold. Rather more interesting is the integrated GPU which, when combined, gives these chips their other name: APU. Ontario is outfitted with the Radeon HD 6250, while the Zacate version, identical in architecture, is faster-clocked and called Radeon HD 6310.

The graphics puppies in the Ontario and Zacate chips appear to be potent for genuine IGPs. Trawling through the specifications, it seems as if the IGP is very similar to a discrete Radeon HD 5450, because, in terms of topology, it's home to a matching 80 stream processors, eight texture units, and four ROPs.

Don't get too excited though, as the faster Zacate chip's IGP is clocked in at 500MHz (compared with 650MHz on HD 5450) and, notably, it has to share any memory bandwidth with the CPU core(s). Both parts of the chip have access to system memory through a single-channel (64-bit) link at a maximum supported frequency of 1,066MHz.

But let's not forget AMD is giving you all this CPU-and-GPU power with a maximum power-draw that's lower than a Radeon HD 5450's, and that's impressive.

Still kind of flummoxed by which chip does what? Let me roll out a table.

Clearer than mud, I hope.

UVD 3.0

These low-power chips should be able to provide a basic computing experience, though AMD helps them out by integrating the latest unified video decoder (UVD) block, now in its third incarnation. This special-function bit of logic takes most of the hard work out of hardware encoding/decoding videos, and the latest version adds in support for hardware-based help for the popular DivX and Xvid Codecs.

Odds and sods

You thought it was just a dual-core chip with some spiffy DX11 graphics bolted-on, right? Well, it is, but it also features a platform interface section. Its job is to route out the onboard video by either HDMI, DisplayPort, DVI or good, ol' VGA. What's more, it has a PCIe x4 interface built in, useful for hanging a separate graphics card from, as well as a necessary 2.5GT/s link to the supporting Hudson chipset.

Hudson FCH

The last piece of the low-power jigsaw is the supporting chipset. Hudson's the name and the single-chip solution, dubbed the Fusion Controller Hub (FCH), provides the backbone on which the computational part of the chip strut its stuff. Plumbed out with up-to four PCIe lanes - primarily used for high-speed interfaces - and the usual suspects in the form of six SATA 6Gbps ports, HD audio and USB 2.0, it's a tidy little package.

Be aware that there are several versions of the FCH, differentiated by the speed of the UMI interface between Hudson and the CPU/GPU, RAID functionality, presence of an integrated Gigabit MAC, and PCI lanes. Phew!

For the desktop?

You know how at the start of this rather lengthy technology preamble I commented on the suitability of Brazos as a low-cost desktop machine? Well, it seems as if tier-one manufacturers want to turn a buck and have prepared solutions with the top-line E350 chip pre-installed on to a mini-ITX motherboard. The thinking makes implicit sense if you don't need the raw power on tap from a pukka desktop chip, yet desire a PC that has supposedly more clout than Intel's Atom.

Without further ado, let's introduce you to the Gigabyte E350N-USB3 box of trickery.