4 x DIMM, max. 8GB, DDR2 1066*/800 / 667 MHz, non-ECC, un-buffered memory
Dual channel memory architecture
* The chipset officially supports the memory frequency up to DDR2 800MHz. Tuned by ASUS Super Memspeed Technology, this motherboard natively supports up to DDR2 1066MHz
Please refer to www.asus.com or user manual for Memory QVL. http://www.asus.com/products.aspx?l1=3&l2=11&l3=534&l4=0&model=1646&modelmenu=2
Specifications are the key word with any board to see what memory is supported. The boards that are out presently still see DDR2 memory as the standard while some offer a degree of support for the new memory. The information seen there on the Asus product page says yes on DDR2.
He was asking about the P5k3 Deluxe; the board that you linked to, PC eye, is the P5K Deluxe; the biggest difference I see between the P5K Deluxe and the P5K3 Deluxe is that the P5K3 uses DDR3. I wasn't sure if you were recommending that board to him, so I thought I'd clarify the DDR3 exclusive thing.