updated 11:00 am EDT, Fri June 20, 2008
Radeon HD 4850 via Diamond
Preempting a formal introduction by AMD alone, both AMD and Diamond have publicly introduced the Radeon HD 4850. Both the reference video card and Diamond's own model are some of the few upper mid-range cards to fit in a single card slot while still outperforming more expensive cards: in benchmarks, the 4850 is known to roughly match the performance of the more expensive GeForce 9800 GTX and the dual-chip Radeon HD 3870 X2. A boost in the number of stream (pixel and vertex) processors from 320 to 480, plus a 625MHz core clock speed and 993MHz memory, is credited for much of the improvement.
In keeping with other Radeon HD 4000-series cards due to be announced soon, the 4850 also introduces AMD's second iteration of its Universal Video Decoder that adds full hardware acceleration for video in MPEG-2 format alongside earlier H.264 and VC-1 boosts. The change further takes the burden of rendering video away from the main system processor and frees it up to perform more important tasks. Support for more advanced visual effects in DirectX 10.1 and OpenGL 2.0 carry over from the 3000 series.
Diamond's own card is shipping immediately and is available today from Amazon at its official $200 price, putting it well below the cost of cards that would normally offer similar performance. AMD itself, ASUS, Sapphire, and other card makers are expected to use the Radeon HD 4850 in the near future, as are larger PC builders.
NVIDIA has quietly countered the 4850 with the GeForce 9800 GTX+, a $230 card which overclocks the stock 9800 GTX without changing features.