Initially at least, AMD Fusion isn’t a direct competitor to Sandy Bridge. The first Fusion chips are based around the new 40nm Bobcat core, aimed squarely at the low-power roles dominated by Intel’s Atom processors. This platform is codenamed Brazos, and it includes both single- and dual-core processors, in two flavours: the regular E series (codenamed Zacate) and ultra low-power C series (Ontario).
The new chips all boast one of two Radeon-branded GPUs (identical but for clock frequency) with 80 DirectX 11 stream processors, plus AMD’s Unified Video Decoder 3 for high-definition media. That means that even the low-power C series should handle complex 3D animations and Blu-ray media. AMD is also fully supporting OpenCL and Microsoft’s DirectCompute framework, encouraging programmers to use the GPU to accelerate general-purpose calculations. For this reason, AMD likes to refer to Fusion chips as APUs – accelerated processing units.
Overall, the Brazos formula is similar to Nvidia’s Ion platform, which marries an Intel Atom CPU to a discrete Nvidia GPU. The difference is that, for obvious reasons, Ion can’t reap the efficiency benefits of combining everything on one die — potentially giving AMD an unanswerable advantage.
Putting Brazos to the test
Since Brazos is aimed primarily at consumer devices such as netbooks and tablets, the chips are mounted directly on the motherboard, rather than socketed. That means you can’t buy a Brazos processor on its own; but if you want to build a home media centre, or a compact desktop PC, several manufacturers offer mini-ITX motherboards with integrated processors at around the £100 mark. We tested Gigabyte’s E350N-USB3 motherboard package, which has the top-end E-350 processor, with support from 2GB of 1,066MHz DDR3 RAM (the board supports up to 8GB of RAM in two DIMM sockets) and a low-power 2TB Seagate Barracuda LP hard disk.
The results were decent, but not stellar. In our application benchmarks, the Brazos system achieved an overall score of 0.53 — higher than any Atom- or Ion-based system we’ve seen, but not by a wide margin. For comparison, our A-Listed netbook, the Asus Eee PC 1001P, achieved an overall score of 0.39, while the Ion-powered Zotac Zbox HD-ID34 managed 0.46.
When it came to media playback, the E-350 had no difficulty rendering video at resolutions up to 1080p in a variety of formats – including high bit-rate Blu-ray rips and streaming video from YouTube HD. Windows Media Center felt responsive, but we noted that CPU usage was around 70% whenever video was playing, and performing more or less any background action caused stuttering. Considering the platform includes a built-in hardware video decoder, we’d expected better: hopefully a future driver upgrade will improve matters.
Read more: AMD Fusion review | AMD Brazos review | Processors | Reviews | PC Pro http://www.pcpro.co.uk/reviews/processors/365131/amd-fusion#ixzz1RtNQ5exR
Gaming performance was the biggest disappointment. Our regular Crysis test refused to run, as did our Just Cause benchmark – again, perhaps a result of early drivers. We were able to run the World in Conflict 3D benchmark, but found the game playable only at Very Low quality settings. With almost all the visual effects disabled, and the screen resolution set to a netbook-friendly 1,280 x 768, the E-350 ran the game at an average of 37fps, dipping to a jerky 16fps at the busiest moments. Switching up to Low quality slashed the frame rate to an average of 15fps. The system’s total power consumption during these tests peaked at 59W, dipping down to 47W with Windows sitting completely idle. For comparison, the Ion-based Zotac Zbox drew just 40W at peak and 24W when idle. AMD has claimed that Brazos will help ultraportable laptops achieve a ten-hour battery life, but these figures suggest that will be a stretch for the E-series chips with their 18W TDP. The C-series chips should prove more efficient, but on this evidence we’d expect performance to be no better than current netbooks.
Is Fusion the future?
It’s important to note that Brazos doesn’t represent the full potential of Fusion. More powerful desktop processors are due this summer, based on different core designs, including the brand-new Bulldozer core. It’s probably the strength (or otherwise) of those chips, more than Brazos, which will shape AMD’s fortunes – and the general direction of CPU technology – in the coming years.
That’s just as well because, sad to say, Brazos is a bit of a damp squib. Even on the top-end E-350, desktop applications suffer from the familiar netbook sluggishness, high-definition video performance is more fragile than we’d like, and 3D gaming is a realistic option only if you’re willing to forego nine-tenths of the visual experience. It isn’t a bad chip, and it could find its way into some appealing netbooks, but the advantage over Atom isn’t compelling enough to make it anything more than an alternative option.
Brazos makes more sense if we look further up towards the mini-desktop and media PC markets, especially if a driver update can tighten up its video performance. Paying £100 for an HD-capable system is an enticing prospect. But these are specialised niches, and Brazos’ lack of headroom is likely to drive cautious customers and system builders to Sandy Bridge. A low-end Core i3 system may cost twice as much, but it will deliver rock-solid video and four times the overall power.
Overall, Brazos has its strengths, but it’s an underwhelming start for Fusion. It feels a year too late given its level of power, and it certainly isn’t the game-changer AMD needs if it’s to make up the ground lost to Intel in recent years. At best it’s another valid option for netbook and nettop manufacturers – and that’s undoubtedly a good thing – but it isn’t going to rock the boat in this form. The real test will come in a few months’ time when Fusion desktop chips arrive.
No comments:
Post a Comment