New Rambus memory types aka PC4200 and PC3200 RDRAM are based on wider 32bit data bus. The today’s RDRAM memory used in systems based on i850 and i850E chipsets features 16bit bus and provides 3.2GB/sec bandwidth.

The mere idea of enhancing the bus this way is very simple. Look. 32bit Rambus memory modules are dual-channel devices combining two 16bit modules in one package. And taking into account that contemporary chipsets supporting RDRAM use exactly two 16bit RDRAM channels, these memory modules will work with i850 and i850E without any additional changes in the chipset architecture. Here 32bit modules working at 400MHz belong to PC3200 RDRAM spec, while those working at 533MHz – to PC4200 RDRAM spec. Now the names of 32bit modules are built the same way as those for DDR SDRAM, when the bandwidth is mentioned in the name of the memory type. ASUS decided to take advantage of this fact when they launched their Pentium 4 solution supporting 32bit RDRAM modules. This mainboard is equipped with two 232-pin RIMM slots for 32bit modules instead of the formerly used four 144-pin RIMM slots for 16bit modules.

ASUS will very soon start shipping this mainboard supporting 32bit PC4200 and PC3200 RDRAM modules and based on i850E/ICH2 chipset to its distributors. The solution will be called ASUS P4T533. Here is a picture of this product:

P4T533 will feature an AGP Pro slot, 6 PCI slots, an optional ATA/133 RAID controller from Promise, an optional network controller from Intel and a USB 2.0 controller from NEC. Also it boasts the entire set of overclocking friendly functions and Q-Fun technology.

Since there are no PC4200 and PC3200 RDRAM modules available in retail now, ASUS will supply its P4T533 with the corresponding memory modules by Kingston.