CMS 16GB (4X4GB) DDR2 3200 400MHZ ECC REGISTERED DIMM Memory Ram Upgrade Compatible with Dell® Poweredge 2800 Ddr2 Dual Rank For Server Only - B48 System Specific Memory - Newegg.com
cpu - 800 MHz DDR2 RAM shows half of memory speed on my machine - Super User
CMS 1GB (1X1GB) DDR1 3200 400MHZ NON ECC DIMM Memory Ram Compatible with HP/Compaq Digital Entertainment Center Z557, Z558, Media 856X, 876X - A114 - Walmart.com
Memory Master 4 GB (2 x 2GB) DDR2 800 MHz PC2-6400 Desktop DIMM Memory Modules MMD4096KD2-800 at Amazon.com