I have several servers: some of them have Xeon E3-1240 V3 and some have Xeon E3-1230 V1. All of them run on Windows Server 2008 R2. I need extremely low latency (even 500 microseconds matters), so I want all CPUs states to remain at 100%. It works with E3-1240 V3 by typing:

Powercfg -setacvalueindex scheme_current sub_processor 893dee8e-2bef-41e0-89c6-b55d0929964c 100 Powercfg -setactive scheme_current

at command prompt (I also set max state to 100% and boost to 100%), the CPU stays at 100% even when idle, but it doesn't work with E3-1230 V1. The CPU state does go higher, but it stays at about 70%.

I use Windows's Resource Monitor and CPU-Z to monitor the CPU state. In CPU-Z the multiplier for E3-1230 V1 keeps jumping from 16x to 33x, for E3-1240 V3 it remains almost constant at 38x.

Am I doing anything wrong? Is there another way to force E3-1230 CPU state to stay at 100%?

  • 1
    In GUI for Power I set it to performance mode and then manually set min state, max state and boost to 100%.E3-1240 V3 stays at 100% when idle, E3-1230 V1 stays at 70% when idle, and only jumps to 100% when under load. I can't go to bios, because these are remote servers, I rent them. – Yekoor Apr 23 '14 at 13:22
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    I have just noticed this in the even viewer for E3-1230 V1: ----- Processor 7 in group 0 exposes the following: 3 idle state(s) 0 performance state(s) 0 throttle state(s) ---- No performance states? And: ---- The platform implements processor performance and throttle state control. Minimum performance frequency percentage: 66 Minimum throttled frequency percentage: 8 --- I set min CPU state for E3-1230 V1 to 100%, but it stays at 66. – Yekoor Apr 23 '14 at 14:30

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