From DailyTech: ATI, the graphics division of AMD, has been aggressively delivering on price and performance for the last year with its RV770-based GPUs. These have been used in Radeon HD 4830, 4850, and 4870 video cards to steal away market share from NVIDIA.
Recently, ATI launched the Radeon HD 4890 using the RV790 GPU, a respun RV770 with a few tweaks and improvements in order to improve its position in the higher end $200+ price bracket. However, most of its sales are in the $100 category and lower price points. Today, ATI delivers a GPU to consumers at that range that NVIDIA can't match.
The Radeon HD 4770 video card that is launching today uses the RV740 GPU, which is the first 40nm GPU in mass production. The GPU consists of 826 million transistors at a core clock of 750MHz, measuring 11mm by 11mm. The Radeon 4770 features 512MB of GDDR5 DRAM clocked at 800MHz, but effectively provides 3.2 Gb/s over a 128-bit bus.
The new GPU has 640 Stream processors, the same number as the Radeon HD 4830 that it will replace. The Radeon 4830 will be quietly phased out since the Radeon 4770 offers better performance at a much lower production cost to AMD. This is offset by higher costs for GDDR5 RAM.
Smaller process geometries have led to higher possible speeds at lower power consumption. The Radeon 4770 board has a TDP of 80 watts. Costs for AMD should also drop significantly, as theoretically a lot more chips can be produced from a 300mm wafer on the 40nm process as opposed to the older 55nm process. However, yields for a new process are never as good as for an older, more mature process.
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