Nanu; Intel 423/478 refers to the CPU Socket configuration as in "Socket 423/478" which is for Intel Pentium 4 CPUs mainboards 845/850 is refering to the Intel chipset number on the motherboard. sdr/rdr I would assume is refering to memory types? sdr being Sdram, and RDR being Rambus memory. <>< Larry Fisk Fisk Computers Fruitvale, Idaho ----- Original Message ----- From: "Nanu Calmanovitz" <[log in to unmask]> To: <[log in to unmask]> Sent: Friday, November 02, 2001 3:53 PM Subject: [PCBUILD] What is? Hi! I'm looking for explanations\info about the following terminology: -Intel 423/478 - main boards 845/850 - SDR/RDR The NOSPIN Group is now offering Free PC Tech support at our newest website: http://freepctech.com