Z440 with E5-1650 v4 doesn't go full multiplier

[HenkVogels]

Hello Community,

I have a Z440 workstation with a E5-1650 v4 CPU.

The clock of the E5-1650 v4 is 3.6GHz/4.0GHz

My multiplier never goes above 38x at 100% load but the full CPU Turbo Boost should be 40x.

The BIOS says Turbo Boost: Enabled

Who knows what can be wrong?

A bit history:

The workstation had original a E5-1620 v3.

I have done a complete clean install.

The system has 8x8GB DDR4 2400 RAM (original).

[DGroves]

intel states that Max Turbo Frequency is a "up to" spec not a guaranteed number it depends on thermal and power limits

while i also agree that you "SHOULD" be able to reach 4.0 one  core that's not true for running all cores to 4.0Ghz

depending on the testing program used you either are not loading the cpu fully or you are loading it fully on all 4 cores and the thermal/power limits are being reached

Intel® Turbo Boost Technology ‡

Intel® Turbo Boost Technology dynamically increases the processor's frequency as needed by taking advantage of thermal and power headroom to give you a burst of speed when you need it, and increased energy efficiency when you don’t.

Intel® Turbo Boost Max Technology 3.0 ‡

Intel® Turbo Boost Max Technology 3.0 identifies the best performing core(s) on a processor and provides increased performance on those cores through increasing frequency as needed by taking advantage of power and thermal headroom.