The Intel X48 Express Chipset

The X48 Express is currently Intel's top-end enthusiast platform, and includes all the features and performance bells & whistles you would expect. Processor support covers the gamut of Core 2 Duo, Quad and Extreme 45nm and 65nm models, as well as Pentium dual-core and Celeron LGA775 models. Front-side bus speeds ranges from 800 MHz to 1600 MHz, and although the X38 unofficially could handle 1600 MHz processors, the X48 is the first, and only, Intel desktop chipset to officially support this FSB speed.
The X48 uses DDR3 memory, and although Intel does not expressly mention DDR2 as an option, several manufacturers have produced DDR2-based X48 motherboards. The X48 also upgrades official dual-channel DDR3 speeds from 1333 MHz on the X38 to a full 1600 MHz, and with 25.6 GB/s of memory bandwidth. These are only "official" speeds, and some high-end motherboards have taken the defaults a bit higher. Intel also offers Fast Memory Access on the X48, which optimizes memory bandwidth, while lowering latencies. Flex Memory Technology, where different sized modules can be used in dual-channel mode, is also supported on the Intel X48 chipset.