If you can afford it, you should look at the quad Opterons. Your interconnects will be less expensive for the same number of CPUs. Others have already answered your question, but I thought you might be interested. Look at the Tyan quad motherboard. Here is a review to look at: http://www.aceshardware.com/read.jsp?id=60000275 Here are specs for power for a quad Opteron cluster we are getting quoted on: Quad 846 Opteron Slave Node at 120V 5A, 575Watts, 1962BTUs/hr I've gotten quotes from Microway, Aspen, and PSSC so far on quad Opteron based clusters so the hardware is available from vendors. Hope that helps! Dow -- __________________________________________________________ Dow Hurst Office: 770-499-3428 * Systems Support Specialist Fax: 770-423-6744 * 1000 Chastain Rd. Bldg. 12 * Chemistry Department SC428 Email: dhurst@kennesaw.edu * Kennesaw State University Dow.Hurst@mindspring.com * Kennesaw, GA 30144 * ************************************************************ This message (including any attachments) contains * confidential information intended for a specific individual* and purpose, and is protected by law. If you are not the * intended recipient, you should delete this message and are * hereby notified that any disclosure, copying, distribution * of this message, or the taking of any action based on it, * is strictly prohibited. * ************************************************************