Hi All,
I have been seeing relatively poor performance on a CPU intensive 8-vCPU VM (W2K8) compared to a 4-vCPU VM (W2K8) on a HP DL585-G7 server with 4 x 12-core AMD Opteron 2.1GHz processors.
I have seen this blog post (http://frankdenneman.nl/2011/01/amd-magny-cours-and-esx/)and it would appear that the internal architecture of the 12-core is actually 2 * 6-core and thus my 8-vCPU VM is being wide-NUMA split across two internal blocks of 6-cores. The split may also not be the same two blocks of 6-cores in the same socket but across potentially different sockets.
AMD have announced the new Opteron 6200 16-core. However this also appear to be built on the same "Bulldozer" building block process as the 12-core older cousin. What do we know of the internal structure here for the 16-core? Am I correct to believe that it is probably a 4x4-core setup to get to the 16-core total rather than a 2x8-core arrangement?
Can anyone confirm the true internal nature of the 16-core server.
Also is there such a limitation in the new Intel Xeon E7-8xxx series. There are 10-core @ 2.4GHz and 8-core @ 2.67GHz. These may be a possible alternative to the AMD but they do cost more.
This is all related to a search for the best way to provide the virtual replacement for physical servers (2x4-core@3.0GHz) which are highly utilised (circa 80-85%). I feel that, based on the evidence I have so far, there will not be a cost effective virtual equivalent due to the very high physical utilisation. I'm trying to rule out all infrastructure issues before throwing in the towel.