Please see the original post - I am in no way recommending to go for every Oracle VM workload to this monster VM - in fact a best practice is to divide whenever possible. But if you can't go this way - that's true in our case - read on for more details I was able to capture.  Good news: customer is running benchmark test on a system with 32 cores (HP B660 with 4x4650 with 8 cores) and 768GB RAM. A monster VM scales fine up to 28vCPUs now and only drops to performance of 24 cores with 32vCPUs. We haven't run yet the application, but it looks like that in this case Hyperthreading (HT) on the previous machine didn't work well. We are looking for the vSphere 5.5 release to try advanced features as well to apply best practices for Oracle tuning on a VMware VM. As posted earlier the document on VMware's Oracle landing page seems to be outdated (2011) here are more recent hints and tips.In the scenario we run Oracle 11.2.0.2 at this point.   These are the key topics we identified in our situation - you might want to visit the following resources that provide further detail and we were looking at:  Thanks to Darryl Smith, Bart Sjerps, Sam Lucido, itzikr, Jeff Browning who provided input and insight.
Does anybody have real world experience with 32vCPUs monster VMs? We have a customer in Austria that got some feedback that beyond 16vCPUs the VM performance doesn’t scale as expected. I received some more information: primarily it's Oracle on a 32core machine - performing unexpectedly less on the VM. On the VMworld 2013 panel I have heard the recommendation for Oracle to turn off NUMA and set HT = 1.  there is more information in these sessions: VAPP4679 - Software-Defined Datacenter Design Panel for Monster VM's: Taking the Technology to the Limits for High Utilisation, High Performance Workloads Sam Lucido and Jeff Browning, did a session on Oracle (VAPP5180- Extreme Virtualized Oracle 12c Performance in a Proven Architecture). if you are interested, however, it doesn't answer my question completely, so still lookin for real world experience:  It’s one of our loyal customers with VMware, VPLEX, VMAX,… and they are in the process to move some of the biggest workloads (DB and more) to vSphere. Thanks in advance!  -         Message was edited by: David Hanacek
Monster VMs performance 32vCPUs experience? beyond 16vCPUs drops?