AMD’s new A-Series chips (codenamed “Llano”) combine a CPU and GPU in a single chip. In issue 165 we looked at the laptop chips; now we have the desktop parts. The A6-3650 and A8-3850 chips head up the mainstream and high-end series; cheaper APUs will follow, along with a dual-core A4 series.
AMD A-Series desktop chips: Click to enlarge.
An A-Series chip offers a different balance to Intel’s Sandy Bridge.
The CPU logic in the new chips is based on the old 32nm Phenom II design. While they deliver slightly better performance AMD has removed the L3 cache, and cut clock speeds: while the Phenom II 970 runs at 3.7GHz, but the A6-3650 strolls along at 2.6GHz. Even the flagship A8-3850 only hits 2.9GHz. And there’s no Turbo Core on these models to push frequencies higher: lesser models will offer dynamic overclocking, but won’t go faster than this.
This gives the A-Series only middling CPU power. In our Real World Benchmarks the A8-3850, with 4GB of RAM, achieved 0.67 overall – well below Intel’s Core i3-2100, which scored 0.79. The mid-range A6-3650 managed 0.64, a score on par with a low-end dual-core Athlon II.
That doesn’t mean A-Series processors feel sluggish. Both chips achieved their best scores in our Responsiveness test, hitting 0.75 and 0.73 respectively. But multitasking scores of 0.59 and 0.56 were disappointing for quad-core processors. If you want an AMD chip to match the Core i7, you’ll have to wait for the Bulldozer architecture, due later this year.
The A-Series uses a 905-pin FM1 socket: you can’t drop a Fusion chip into an older motherboard, but you can use an old heatsink
Happily, desktop performance is only half of the story. Inside every A-Series processor you’ll also find a DirectX 11 Radeon GPU. A6 processors enjoy 320 shaders running at 443MHz, while A8 models bump this up to 400 shaders at 600MHz.
This is an impressive amount of GPU power. The A6-3650 romped through our Low-quality Crysis test at an average of 53fps at 1366 x 768, and kept up a playable 31fps at 1080p. The A8-3850 nudged up to 55fps and 34fps. Even at Medium detail, the game remained playable at 1366 x 768, with the A8 averaging 34fps and the A6 hitting 30fps.
These scores are the best we’ve seen from an on-chip GPU. Intel’s Core i5-2500K processor, managed only 38fps at 1366 x 768 with Low detail, plummeting to 13fps at Medium detail.
The A-Series’ GPU shines in gaming but the main focus of its design is on OpenCL performance. The steadyvideo smoothing technology included in drivers is one example, as are Chrome, Firefox and Internet Explorer, which all support GPU acceleration.
The A-Series certainly isn’t a me-too rival to Sandy Bridge. Intel’s chips deliver stunning desktop performance but only lightweight 3D graphics; the AMD chips offer a distinctly different balance.
Whether it’s a better balance is a subjective question. If your priority is CPU performance, an Intel processor is a better buy. And, although the A-Series’ graphical performance is impressive, 3D-gaming enthusiasts will still get more detail and higher resolutions from a system with a standalone graphics card.
But if you’re looking for an all-rounder, an A-Series chip could be just the thing. Although desktop performance isn’t stellar, it’s fine for everyday use, and when it comes to games even the latest titles are perfectly playable.
At the moment the A8-3850 is the only APU available at retail, although the A6 should arrive soon. As for which one to pick, unless the A6 comes in significantly cheaper, the A8 is our favoured model.