SSE CPU Test and Overclock

[GamerXP]

Hello. I was overclocking my CPU and used PerformanceTest to compare results. After overclocking my Intel Core i7-6700 to 4.5Hhz I found every score increased... but Extended Instructions (SSE) Test. It decreased like 3 times. Could anyone know why this is happening?

Before Overclock:
https://i.gyazo.com/8d280c3671ce5aea...e98e4870ac.png

After Overclock:
https://i.gyazo.com/46ee9191e5236828...a0cd74865e.png

[David (PassMark)]

The Extended Instructions (SSE Test) test will perform testing using sub-tests for FMA, AVX and SSE (or only those that are supported in a particular CPU).

We haven't tested this ourselves, but this is what I have read recently.

AVX instructions put more strain on a CPU. AVX workloads consume a lot more current than ones that use the default instruction set resulting in higher thermal output and so need lower clock speeds to compensate. Power users can configure Broadwell-E to only reduce its clock speed when it detects AVX instructions while maintaining higher frequencies for other instructions. This applies to Kaby Lake as well and maybe other CPUs. not just Broadwell-E.

On some motherboards this is implemented via a "AVX ratio offset" in BIOS.

So this likely what happened. The use of AVX instructions was too much for your CPU & it was forced to underclock itself to keep within current & heat limits.

[GamerXP]

Thank you for reply. I'll try looking for those settings in BIOS then and repeat the test.

EDIT:
I googled about AVX and found the reason. It seems my custom BIOS with unlocked BLCK have unsolveable problems with AVX performance. Should have bought K version of CPU I guess. Thank you for your help.