Turbo mode w/ XenServer 6.5

The frequency for all CPUs appears to only ever be at max (non-turbo). It does not appear to scale or reach turbo frequencies.

Using XenServer 6.5 on C240 M3s with the following BIOS modifications:
Power Technology = Custom
Energy Performance = Performance
P-STATE coordination = Software All
Fan policy = Performance

Grid card = K2

CPU-Z reports a static 2.8ghz

Reference material used:

Any ideas on why turbo frequencies are not appearing on VM cpus? Thanks.

Since it’s the hypervisor that controls the clock speed, it’s a good question to ask Citrix, probably best place is on their forum


It may also be that the C240 M3 doesn’t allow OS control, or it could be that the way that CPU-Z measures clock speed inside the VM means it’s not seeing the variations in clock speed due to being obstructed by the hypervisor.

Thanks Jason. Yes… I have opened cases with Cisco and Citrix as well as posting on both forums. Hope to figure things out soon.

I see exactly the same thing, with R720 servers and even with XenServer 6.5 SP1. Not sure if I’m never pushing limits but this does seem odd. Definitely, Citrix is the place to go for supprot. Let me know if you hear anything! I assume you are familiar with http://support.citrix.com/article/CTX200390 and http://xenserver.org/partners/developing-products-for-xenserver/19-dev-help/138-xs-dev-perf-turbo.html .

I’m not sure if I add anything to the discussion but I see the same issues. I have enabled both OS Controll and High Performance but see the same results. It just “idles” at 2,6Ghz on a 2690 v3 processor. I have a DELL R730 with GRID K1’s. I use Prime95 to stress test the CPU. If anyone has had any luck with Citrix support please let me know.