CPU Performance Issues on VMWare ESXI & Citrix XenServer Performance Question I posted something a few weeks ago here about the wisdom of virtualizing a processing computer. I wanted to follow up with a few questions. 1 - Performance. The computer I'm coming from / virtualizing is an I7 4770K, 8GB ram & Windows 7. The computer I moved to is an HP DL360 G8 w 32GB ram & dual E5-2660's running ESXi 6.5. The VM benchmarks of the CPU's were very similar (11K) running CPUMark inside a virtual machine with one of the processors (8 cores) assigned to the VM when compared to the physical machine. BUT I'm having performance issues in real world use. There are two processing running that slam the processor (VM performance images attached). One process is important & needs to keep up in order to keep a scanner from slowing down. The other is a background processing service that nothing relies on - it's just splitting files up. It can get done when it gets done but they both need to run at the same time. I think I'm going to be able to eke out similar performance based on testing I was doing last night by A - Changing VM vCPU's to 16 (All cores on both processors) & turning off hyperthreading. B - Setting affinity for background process to two cores with low priority. C - Setting affinity for realtime process to all other cores with high priority. I've enabled all hardware virtualization features I can find in the BIOS (They were enabled already). I'm also doing Hardware CPU & MMU on my VM. This is the only machine running on this hardware. The read / write speeds are faster than the physical machine (175MBs). So in summary it's taking me 2X the processing power to get the same performance (I've tested Disk I/O, RAM is the same on VM & physical machine. Processors get hammered as you can see from the pic) Am I missing some type of configuration that can drastically increase my CPU efficiency? If not - I think it's livable if not preferable. But that brings me to my second question. 2 - VMWare vs XenServer. I'm going to have to either license VMWare with their small business 6 processor / 3 server license or move to XenServer. Can anyone comment on processor efficiency of XenServer vs ESXI? Based on everything I'm reading it looks like MSSQL Server vs MySQL. I'd prefer to go with something that won't cost me licensing if I start moving my entire environment to it but have no desire to go down blind alleys with lots of PITA issues (what happens with open source stuff a lot of times).