> Nobody answered my original question, can you fill a motherboard with > four DDR2 slots up to 8GB at all? Intel's DP965LT motherboard claims 8GB support with 4 DDR2 dimms. http://developer.intel.com/products/motherboard/DP965LT/index.htm if you have 4 dimms in this chipset, you're limited to 667Mhz memory bus, with 2 dimms, and the right memory timings, you can get 800Mhz memory timings. All memory used in P965 chipsets must be 1.8V compatible. I peeked at prices on newegg, 2x2GB dimm kits are $430-$600 each, so 8GB ram will cost between $860-$1200. This whitepaper on 965 chipset memory technologies details the specifics of whats supported and how the memory timings interact. http://download.intel.com/design/chipsets/applnots/31320702.pdf I see nothing about any degrading above 4GB, except that 2 x 2GB DDR2-800 is supported, while 4 x 2GB runs at DDR2-667 speeds... I wonder if the previously discussed performance degrading on the Asus board was in reference to PAE required to allow 32bit OS's with > ~3GB ram ? Note this degrading the memory clock when you fully populate all the rows is not at all uncommon. Many Opteron configurations have similar limitations.