intel.com -- doc. #252523

The 82865PE MCH supports FSB frequencies of 400/533/800MHz. The 82865P MCH supports FSB frequencies of 400/533MHz.
For the 865PE chipset, the memory can be 266/333/400 MHz Double Data Rate (DDR) memory components. For the 865P chipset, the memory can be 266/333 MHz Double Data Rate (DDR) memory components.