1 Reply Latest reply on Feb 17, 2016 8:18 AM by Replete

    Why does my i7-4710MQ not achieve even close to max turbo multipliers?

    Replete

      Hyper Threading Enabled:

      UBebco6.png

      (Prime95 running 8 threads on Blend torture test, CPU-Z, ThrottleStop showing active Multiplier information, Intel Extreme Tweaking Utility showing 0% thermal throttling)

       

      CPU Multipliers applied in various scenarios:

      • Idle: 33/34x (I expect 25x)
      • Prime95 1 core (2 threads) = 29/30x
      • Prime 95 2 cores (4 threads) = 27x
      • Prime 95 3 cores (6 threads) = 27x
      • Prime 95 4 cores (8 threads) = 27x

      Temperatures:

      • Idle: Around 44C
      • Full load: Around 75C
      • These values are VERY typical for this processor's use case (mobile workstation)

      Voltage: 0.96v



      Hyper Threading Disabled:

      4DxExbh.png

      (Prime95 running 4 threads on Blend torture test, CPU-Z, ThrottleStop showing active Multiplier information, Intel Extreme Tweaking Utility showing 0% thermal throttling)

       

      CPU Multipliers applied in various scenarios:

      • Idle: 33/34x (I expect 25x)
      • Prime95 1 core = 31x
      • Prime 95 2 cores = 30x
      • Prime 95 3 cores = 28x
      • Prime 95 4 cores = 25x

      Temperatures:

      • Idle: Around 55C
      • Full load: Around 68C
      • The higher idle temperature is probably because of the higher voltage - is this normal??

      Voltage: 1.1v

       


      Questions:

      1. What is causing this unexpected behaviour? (Intel XTU above indicates 0% thermal throttling)
      2. What is the throttling algorithm?
      3. What can I do to further diagnose the issue?
      4. Why does The Intel XTU Stress test cause the CPU to behave as I expect?oLk99UD.png

       

       

      I have tried:

      • Overriding multipliers in XTU - no effect
      • Disabling SpeedStep - stops turbo behaviour completely, stuck at 25x multiplier
      • Increasing maximum current draw in BIOS and XTU for various scenarios - no effect.
      • Forcing fan to 100% even when idle - no effect