Prime95 (V26.6) seems to override UEFI defined power limit.

The_Tester

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Nov 22, 2014
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Relevant specs (full specs in profile)

Motherboard: ASRock Z97 Extreme9
CPU: Intel i7 4770k

The issue with Prime95 is something of an old issue for me but me and a friend got to talking about it and it reminded me of this (anywho...) The problem comes from the program seemingly overriding the long term power limit I set for my CPU via UEFI. In what I will call max mode I've got a short term and a long term power set. The problem is i've ran Prime95 well over the amount of time I set for short term. The CPU power doesn't change (for example: 100W short "10sec" 80W long and ran for a full minute and was still hitting 100W). It just keeps pegging it out to whatever I set the short term limit to. Also it doesn't matter what UEFI revision I use.

I've confirmed this by setting a very low short term of about 50W and long term of 30W. The UEFI settings respond accordingly with everything I do except Prime95, it will sit there at 50W. In this case for however long I let it run. I went one step further and set a short of 100 and long of 30 and looked at the wattage display of my UPS and it didn't change with Prime95. Anything else I was doing and it responded exactly as it should. I went even further and took V*A measurements off the PSU power cord to confirm no change in power draw (power is power and power don't change so the actual number I was getting didn't matter). Also, no I didn't add/subtract the few watts other stuff used like ram and fans and all that. I made a such a large gap with the V*A measurement it would rule out simple error.

Anyone else had Prime95V_26.6 (or any other revision) peg the CPU to the MAX limit regardless of BIOS/UEFI settings?