On 09/15/10 2:19 AM, Rudi Ahlers wrote: > Hi all, > > I'm just curios and would like some input from the community on this > one. We're busy budgeting for a couple of new servers and I thought it > would be good to try out the Core i7 CPU's, but see the majority of > them don't offer VT-d, but just VT-x. Looking at the LGA1366 range, > only the "Intel lga1366 i7 980XE" (from the list of what our suppliers > stock) have VT-d, and it costs 4x more than "Intel lga1366 i7 930" or > 2x more than "Intel lga1366 i7 960". From a budget perspecitve I could > purchase 4 more CPU's, which could translate to 40x - 80x more VM's > being hosted for the same capital outlay. Experience has shown that we > under-utilize CPU's by a great margin and memory / HDD IO is our > biggest bottleneck on any server. > > So, if VT-d really necessary? > We mainly host XEN virtual machine for the hosting industry, i.e. we > don't need / use graphics rendering inside VM's, or need DAS on the > VM's, etc. > Core I7 is the branding for the desktop CPU family. The Server processors are branded Xeon 5500 and 5600 (for dual socket servers) and Xeon 7000 for 4+ socket servers. Typically, desktop processors go with desktop motherboards which don't support ECC memory, probably don't have remote management features, likely don't readily support redundant power, and often have only a single NIC onboard. A server board will likely have significantly more IO bandwidth, oriented towards network and disk IO rather than graphics. IMHO, the dual socket 5600 family is the sweet spot of price/performance for a VM host, with 2 x 6 cores, and typically 12 memory slots (2x3 per CPU). populate the memory with 6 matching DIMMs for best performance.