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In the Windows Resource Monitor's CPU tab, there is a status box and graph for the "Maximum Frequency", right next to the "CPU Usage" values. What does this mean? The value is sometimes over 100% on my system... what could that imply?

resource monitor

By looking at CPU-z's real-time report of the processor's clock speed, it seems to be loosely related to what frequency the CPU is running at, which would imply that it means "percent of maximum possible frequency the CPU is running at"; this would be of relevance on systems with SpeedStep and/or TurboBoost technology (or similar). Furthermore, setting the system to "power saving mode" lowers the "maximum frequency" value to around 60%, while setting it to "high performance" mode sets it to around 110%. However, the percentage does not seem to exactly correlate to the CPU speed being shown. What value is this actually representing then?

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  • How many CPUs do you have? Are they overclocked? Does your BIOS correctly detect you CPU? Apparently there are different ways of detecting the maximum CPU frequency. support.microsoft.com/kb/888282
    – Mikel
    Mar 13, 2011 at 7:05
  • @Mikel: I have a single Core i5 M430, which is a hyperthreaded dual-core processor. It is not over-clocked, but does have turboboost. BIOS detects it normally.
    – nhinkle
    Mar 13, 2011 at 7:22

4 Answers 4

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It simply means of the total maximum of your processors normal speed.

With speed step, power saving and everything else disabled, this should always read 100%.

If you have power saving on your laptop that under clocks your CPU compared to the stock speed, it will report a lower percentage.

If you have turbo boost or similar, it will report a higher percentage.

So, again, this is the current maximum percentage your processor can currently run when compared against its reported normal speed.

I am not 100% sure, but my guess is that if you overclock, the overclocked amount would be the "base" speed to Windows and overclocking by 20% would not show a 120% maximum frequency - this is just guessing, I have no way to test.

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  • It only reports speed changes effected by the system itself with respect to its nominal speed as per BIOS settings, be them default or overclocked. As mentioned these include SpeedStep and Turbo Mode, but also speed reductions due to the "passive cooling" power management option or throttling effected by the system due to overheating.
    – Mark Sowul
    Mar 13, 2011 at 7:43
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    This seems like a reasonable answer, though if anybody finds any official documentation about what it means, I'd like to see it.
    – nhinkle
    Mar 15, 2011 at 21:32
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    I don't think my experience shows this to be true. I'd like to see what MS says it means, like nhinkle.
    – music2myear
    Feb 14, 2012 at 21:27
  • does this drop if the CPUs thermal throttling enables?
    – Divin3
    Feb 25, 2016 at 4:40
  • My Maximum Frequency would never go over 30%, making my PC very slow at times. I figured out how to adjust it back to 100% to correct the problem, and blogged about it at blog.danskingdom.com/…
    – deadlydog
    May 4, 2022 at 0:50
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According to an answer here:

Maximum Frequency in Resource Monitor is the same as the Processor Performance \ % of Maximum Frequency counter in Performance Monitor.

For example if you have a 2.5 ghz processor which is running at 800 mhz then % of Maximum Frequency = 800/2500 = 31%. So the processor is running at 31%, or 800 mhz, of the processor's maximum frequency of 2500 mhz (2.5 ghz).

The "best" percentage of maximum frequency is subjective. Basically, you want the CPU running at a frequency that is fast enough to do what you want while using the least amount of power so it doesn't drain your battery or increase your electric bill unnecessarily.

Your power plan in Windows is part of what determines the frequency as well as settings in the computer's BIOS.

Take a look at the section Processor power management (PPM) may cause CPU utilization to appear artificially high in this article: Interpreting CPU Utilization for Performance Analysis

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  • The second link is not valid anymore :(
    – Putnik
    Jul 18, 2023 at 12:16
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Very late reply, but I just noticed that my percentage in Resource Monitor for CPU frequency is 129%, which corresponds with my overclock. I have a 3.4 GHz Intel i5 that is overclocked to 4.4, which is a (1000/3400) * 100 = 29.411% increase over stock speed. Turbo Boost for my processor (the factory boost to frequency) was 3.8 GHz, but this also showed above 100%. Basically, the frequency your processor is listed at on the box and in CPU-Z at its maximum stock frequency (without Turbo Boost) is what Resource Monitor takes to be 100%.

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7

Just to add that on a modern multi-core computer where unused cores are parked (turned off) to conserve power, the displayed percentage can be much less than 100%.

I have seen values of 30-50% on an unencumbered 8-core computer.

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  • 2
    This isn't an answer, it should be a comment.
    – nhinkle
    Feb 2, 2015 at 9:23
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    @nhinkle: Disagree. The other answers date from before parked cores existed and were correctly handled by the OS. They deal with frequency under/over-clocking. Parked cores and their effect on this number are mentioned nowhere, but with modern processors they will have a much bigger impact than clocking. Please undo your downvote.
    – harrymc
    Feb 2, 2015 at 12:36

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