How to detect thermal throttling

cpuperformance

I have a Dell XPS 15 Laptop, i7-2720QM CPU, 2.20 GHz, Win 8.1 which currently slowed down significantly. Fan goes on quite often.

I have checked the following:

  • sufficient free disk space > 10 GB
  • no significant new software installed.
  • So suspicious entries in System log.

Therefore I suspect it is an thermal throttling issue. Before changing/cleaning the fan which requires quite a lot of screws to open at the XPS15 I want to confirm this suspect more. I have tried out several tool get more evidence on this. Max CPU temperature is mostly around 78 °C, at low load operation ~ 55 °C. (Example screenshot below)

Anyhow I couldn't find a tool which, directly showed me if CPU throttling is currently active. (Or I at least I couldn't identify the parameter indicating this)

Questions:

  • With which tool can I see directly if thermal throttling is
    activated?
  • At which parameter shall I look?

Edit:

Some more observations: AT full load I reach temperature up to 90 °C. The cpu speed (measured with Prime64 & CPU-Z) stays almost constant at 2.2 Ghz, while it seems to allow overboosting with 3 GHz at low load). I additionally found out that CPU-Z displays the factor `Multiplier' in the range of 22 .. 24, whilst this factor is 33 at low load. Is this factor a additional measure for thermal throttling? What is the expected value without throttling (is it 33)?

screenshot

Best Answer

In order to find out whether your CPU is actually throttling, you should be able to use Intel's Extreme Tuning Utility (XTU). I run it on my Ivy Bridge (3rd Gen) systems, but it should work the same on your Sandy Bridge (2nd Gen) CPU.

The Extreme Tuning Utility can directly indicate whether the CPU is throttling or not (see screenshot), and it is also a very convenient tool for observing other information such as CPU utilization, temperatures and frequencies.

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