The Effects of HP's Power Profile on vCPU Performance

When you buy a new HP server it comes with the BIOS setting HP Power Profile set to Balanced Power and Performance. That sounds good but is bad - at least for CPU performance in a VDI environment.

When we prepared our servers for use as virtualization hosts for Citrix XenDesktop we took great care to configure the HP Power Profile for Maximum Performance:

BIOS setting - HP power profile

That fixed the problems with really awful CPU performance we had in the beginning. But still - some VMs were performing worse than others. When I looked at the problem I soon found a VM with bad CPU performance. I ran some benchmarks, comparing it to a “good” VM:

Test setup:
CPU: Xeon E5-2670 2.6 GHz
Hypervisor: VMware ESXi 5.0 Update 1
VM OS: Windows 7 64 Bit
VM configuration: 2 vCPUs

BenchmarkGood VMBad VM
Cinebench 11.5 CPU » more is better2.201.48
NovaBench CPU Test » more is better262204
Super Pi 1M [s] « less is better13.232.2

Depending on the benchmark, the “good” VM is between 28% and 244% faster than the “bad” VM. That is a lot!

I suspected the power profile setting of the server hosting the “bad” VM to be wrong, but how to check without rebooting the server and accessing the BIOS? These are production systems and we cannot use vMotion to move the VMs off the server because the VMs are on local storage. Luckily the power profile setting is not only available from the BIOS, but from the iLO console, too. It can even be changed from iLO, taking effect immediately:

iLO Power Settings

Sure enough, the “bad” VM was on a server with incorrectly configured power profile. Switching it to HP Static High Performance Mode fixed the issue. Strangely, the settings are named differently in BIOS and iLO.

If you want to know more about power profiles and power regulator: HP has a whitepaper on the topic.

CitrixVCPUVMwareXenDesktop

Comments

Related Posts

Shutting Down Unused Persistent XenDesktop VMs

Shutting Down Unused Persistent XenDesktop VMs
When you use XenDesktop the only way it makes sense you may find that Citrix has not really put much effort into making that a smooth experience. Persistent is a Second-Grade Citizen XenDesktop is really designed to be used with pooled desktops - machines that are reset to a pristine state when the user logs off. Of course, stateless desktops are much better (and, importantly, cheaper) served from XenApp. This has been the topic of many a debate which I will not repeat here. But I will state that if you give a so-called knowledge worker a personal desktop, you better make sure that desktop is persistent.
Citrix/Terminal Services/Remote Desktop Services

Latest Posts

Fast & Silent 5 Watt PC: Minimizing Idle Power Usage

Fast & Silent 5 Watt PC: Minimizing Idle Power Usage
This micro-series explains how to turn the Lenovo ThinkCentre M90t Gen 6 into a smart workstation that consumes only 5 Watts when idle but reaches top Cinebench scores while staying almost imperceptibly silent. In the first post, I showed how to silence the machine by replacing and adding to Lenovo’s CPU cooler. In this second post, I’m listing the exact configuration that achieves the lofty goal of combining minimal idle power consumption with top Cinebench scores.
Hardware

Fast & Silent 5 Watt PC: Lenovo ThinkCentre M90t Modding

Fast & Silent 5 Watt PC: Lenovo ThinkCentre M90t Modding
This micro-series explains how to turn the Lenovo ThinkCentre M90t Gen 6 into a smart workstation that consumes only 5 Watts when idle but reaches top Cinebench scores while staying almost imperceptibly silent. In this first post, I’m showing how to silence the machine by replacing and adding to Lenovo’s CPU cooler. In a second post, I’m listing the exact configuration that achieves the lofty goal of combining minimal idle power consumption with top Cinebench scores.
Hardware