This memory kit contains two 4GB modules designed to enhance the performance of your IBM server. These high-speed, DDR2 registered DIMMs are synchronized to the processor so that once addressed, data can be transferred on both edges of the clock signal. This takes advantage of the improved performance of the 667MHz dual front-side bus architecture of the XA-64e third-generation chipset and the 64-bit Xeon MP processor. The memory bus transfers data at up to 5.3GB per second.