4 Replies Latest reply on Nov 16, 2015 8:15 PM by Sankar

    RAPL power limits

    Sankar

      Is there a way to disable power limits enforced through RAPL registers? I tried using the power governor (Intel® Power Governor | Intel® Developer Zone) to disable the power limit settings but it doesn't seem to work.

       

      I am running few workloads that stresses CPU and iGPU on the processor and the total power consumed could exceed the power limit of 15W. The TDP for the processor (i3-5010U) is 15W and the default setting for the RAPL power limit is set to 15W at a time window of 20 seconds. While running the workloads, the limit is enforced and I could notice the package power is reduced to stay within 15W limit. I should note that RAPL lock bit is not set. I tried the following:

       

      1) I tried bumping this limit to 25W using power governor tool but I could observe the same throttling effect after 20 seconds and the power of the package is brought down to 15W.

      2) I tried disabling the power limit altogether using the governor tool but that doesn't seem to work - the power limit stays enabled.

       

      I would like to understand if there are other power limit setting supported in the processors or if power limit setting is enforced through BIOS. Any pointers would be very helpful.