Biostar P4M900-M4 DDR2 533/667 LGA 478 VIA P4M900 MATX Intel Socket 478 pin Motherboard Socket 478 Supports Intel Pentium 4/Celeron D Processor Supports FSB 400/533/800MHz rts FSB 400/533/800MHz The actual memory size may be less than 4GB for the reservation for system usage under Windows XP, Windows XP 64-bit