also me (Core i5 750 on Gigabyte GA-P55-UD4)
rated: 2,67 GHz (multi 20)
Win7: 2,93-3,2 GHz (when under load on, somewhat fluctuating because of TDP/Temp, multi up to 24)
Win10: 2,8 GHz (permanently when at load, NEVER more, multi always 21)
* no load: correctly switches down to a multi of 9 with massively reduced voltage - for both Win7 and Win8
* Win8 must have turboboost enabled - but only 1 clockstep, not up to 4 like specified. was using all 4 clocksteps in Win7
Please be aware that the Intel® Turbo Boost is enabled by default in all Intel® processor that support the feature and the only way to enable it or disable it is by accessing the BIOS. This option may not be available in the BIOS depending on the Computer Manufacture.
Here you can find more information about the technology:
A processor running with Intel® Turbo Boost can increase the processor speed but it does not necessarily means that it will reach the Full speed because it depends upon a number or factors:
- - Type of workload
- - Number of active cores
- - Estimated current consumption
- - Estimated power consumption
- - Processor temperature
has nothing to do with it. System was nicely using turboboost up to its maximum multi of 24 with Win7. After update to Win10, Turboboost is still used, but only up to multi of 21. Stock multi is 20 (i5 750).
Have changed nothing in BIOS after update. No overclock, using "optimized defaults". Even switched back to Win7 (on behalf of temporarily restoring Win7 image) and turboboost ran up to 24 like I always knew it. Back to Win10, I'm limited to 21, even for light singlethreaded integer code like eg. zipping or hashing.
Looks very much like a driver/CPU governor issue in Win10 to me.
Still annouying since it costs me 12% gaming performance (I'm CPU bound, did a quick bench). Overclocking is no solution since I had to disable Speedstep on this board which would make the CPU run always at 3++ GHz with 1,3V - and I need to be able to leave the machine running almost always without driving me poor for electricity.
Would be a good service from Intel to push MS to fixing such issues quickly!
Win10 now uses all turboboost steps up to the max of x24
solution was to explicitly enable turboboost in BIOS. hat it set to the default of "auto" which worked beatifully in Win7, but Win10 needs it to explicitly set to enabled.
correction: it is the "C3/C6 states support" feature that modulates the maximum multiplier:
disabled: max multi=21 for both Win7 and Win10
enabled: max multi=24 for both Win7 and Win10
auto: max multi=24 for Win7 - but 21 for Win10 !!!