I'm using a EVGA Z390 Dark MB, with 9900k, its clocked to 5.2ghz using the robot in bios, but in windows only using 4.9ghz in cinebench and other problems alike.
 
strangely it does spoke to 5.0ghz every so often under normal usage..
 
So what have I done wrong, or is normal? if so whats the point of the oc if its going to run at 4.9ghz? 
 
Thanks.

The max temp is 65°c when stress testing in bios.  Just wanted to make sure that windows wasn't stopping the mulitpiler somehow, as its at 49x (from what I can see).
 
I have a large external rad (Mo-Ra3 420Pro), twin d5 pumps, Heatkiller Iv CPU block etc.  So cooling shouldn't be the issue, clearly this is the thermal transfer rate maximum, as water cooling is overkill, a direct die would be only way to bring temps down from this figure (physically, clearly a better OC lower voltage would be less heat).
 
I'm not happy with 4.9ghz. :D If I can improve it I will though :)
 
 

I presume it is just no a stable OC and dropping it to 4.9Ghz, I can see with E-LEET X that it is quickly jumps to 5.2Ghz then instantly drops to 4.9ghz, however the task manager only reports 4.9ghz.
 
I thought if it could pass the OC Stress test in the Bios (2 hours no problem) then it would run 5.2ghz in windows... 
 
Just want to clarify if there is anything I can do about it or is 4.9ghz the best my chip will do. (as I was a little surprised when it clocked to 5.2 so easily in bios)
 
Thanks for you help.

That worked perfectly, it held 5.2Ghz throughout the whole cinebench, scoring (in R20) 5360 points... however the cpu ran at 93-95°C throughout! eek!
 
So what have I learnt, I need to learn how to overclock my CPU properly and not let the bot do it applying large voltage, and AVX isn't a bad thing... It was set to 3, I might just back it off to 2, hopefully that will give me a solid 5.0ghz to work with for now :) 
 
 Much appreciated :D 

AVX offset -3 was populated. The AVX offset downclocks your CPU by the stated value so that it increases stability. When you had 5.2 with an AVX offset of -3, you would get 4.9 anytime there was an AVX instructed load.

The AVX offset can spare you tons of heat and instability when you are using AVX instructions, and if the offset is set to 0 and you get instability, then you can start changing just the offset count to regain some of that stability back.

You should leave the AVX offset at -3 if you want to keep the standard 5.2 ghz without AVX instructions. Just turning it to 0 will do exactly what you experienced, and generate a ton of extra heat, which will degrade performance rather than boost it.

the_Scarlet_one
You should leave the AVX offset at -3 if you want to keep the standard 5.2 ghz without AVX instructions. Just turning it to 0 will do exactly what you experienced, and generate a ton of extra heat, which will degrade performance rather than boost it.

Don't you love it when someone says that they agree with something that you didn't say?