Xeon E5-2403 CPU Frenquecy stuck at 1.2 GHz, why?

[PMouf]

I've been having a real bizarre problem on my server running Windows 7 Embedded. The CPU is a Xeon E5-2403.

For starters, the CPU is capable of clocking up to 1.8GHz. In normal conditions the processor frequency, multiplier, and wattage throttle depending on how much work the machine is doing. At idle it's 1.2GHz, 10x multiplier, and about 18 watts. At full load it jumps up to 1.8GHz, 18x, 30watts. So its jumps between the high and low without a problem. I'm using RealTeamp app to monitor the CPU. BTW, the power profile is set to high performance in Windows.

Once and a while the CPU will get stuck at 1.2 GHz, 10x, 18watts no matter how much work the machine is doing. This results in the machine being extremely slow and unresponsive. CPU usage is very high and doesn't recover. Rebooting the machine does not help either, it ends up in the same state. The only solution is to power down, unplug the power cables, and wait 30 seconds. Once I power it back up everything is ok.

Does this have something to do with the power management in Windows? or how windows is controlling the processor? If yes I would assume a reboot should solve the issue since I'm restarting windows. Maybe processor or bios problem? I'm trying to isolate that the problem is not windows or hw related..

Any thoughts would be appreciated.

[Allan_J_Intel1]

Thanks for joining the processor community.

I understand the processor idles 1.2 GHz no matter the workload of your system.

I see the processor features Enhanced Intel® SpeedStep® Technology (EIST), this will lower processor speed to save power, you may want to check BIOS settings and disable EIST and see if would help to keep the processor working at full speed all the time.

Allan.