12. System RAM: DDR Or DDR2?

Every HTPC needs RAM, but which kind depends on the motherboard and its memory sockets. SD-DDR remains the most widely-used flavor of RAM, but DDR2 is catching up quickly.

Nearly all the motherboards we've looked at work with SD-DDR modules; only the Intel-based Gigabyte motherboard requires DDR2 RAM. The AOPen i915GMEm-HFS motherboard can handle either two SD-DDR or two DDR-2 DIMMs. So for this motherboard, we would opt for two 512 MB DDR2 modules from Kingston.

Corsair CMX512 500 MHz

Information on the DIMM package

Infineon SD-DDR 266 MHz

Information about memory timing and module size.