The 5900 XT’s memory operates at 350MHz (700MHz effective), 75MHz below the 5900 Ultra and 125MHz slower than the 5950 Ultra. This provides the 5900 XT graphics core with up to 22.4GB/sec of peak memory bandwidth, the same figure as ATI’s RADEON 9800 PRO 256MB and 8GB/sec more than GeForce FX 5700 Ultra, which was the previous leader in this category in the mainstream segment.
Despite the slower memory frequency (700MHz effective versus 850MHz), the 5900 XT is able to keep up with the GeForce FX 5900 128MB in many benchmarks thanks to the lower memory timings its 2.8ns BGA memory boasts.
Due to the reduced frequencies of the graphics core and memory, 5900 XT board manufacturers are able to utilize a simpler board design with reduced power and heat requirements. An external power source is still needed, but the board requires significantly less power circuitry and smaller coolers. Video input and hardware monitoring functionality are also sometimes left out in order to further reduce production costs. Souce