Alceryes is spot on
As a fellow 9900K owner let me just say that 240 AIO IS NOT enough to cool that 9900k on benchtesting. I'm sure it will cool just fine in gaming and surfing the interwebs. Cooling that CPU is everything! Colder it is, higher it will boost. I was on a 280 AIO and i could get stable 5.0 & 5.1 GHz OC on most benchtests except for AVX. Stepped up to a 360 AIO and its better by far and i can achieve 5.2GHz on all benchtests with temps in the mid 80c's - still hot yes, but i can complete the tests without a BSOD where as on my 280 AIO it would run for a minute or two and BSOD.
My gaming temps are in the mid to high 40c's when gaming and idles at a cool 27c. Only time it gets hot is when i overclock the piss out of it for benchtests. I can hit 5.1GHz all cores using 1.23V and monitoring via HWiNFO64
Another element to this is what motherboard do you have? Higher end motherboards have better VRM's and better stability for OC'ing. Also what is your settings for your overclock? I'm not concerned about AVX personally, there is nothing i do or run for long periods of time to stress my CPU like running prime etc.
I would upgrade your cooler if anything. If you can run other benchmarks like 3D Mark, Cinebench R15, R20 and stress it for 30 mins with no BSOD's i would say your fine. What do you use your PC for? Do you have your cooler setup on a fan curve? Pump on extreme when benchtesting?
Thx for reply!
I think I've just got a bad chip. I need 1.34 to hit 5.0GHZ with LLC on level 4 and uncore set to 4.7 for true stability. Lower voltage than that and I'll bsod if, say, I run Prime 95 non AVX and then open a game concurrently. The extra demand is enough to crash the rig. 1.34 is what I need for full stability (not inc AVX). I'm running XMP. Mainboard is MSI MPG Z390 gaming pro carbon AC
With AVX, I bsod after 20 seconds, and my temps hit 100c. With a -2 offset, I can go past 20 seconds, but temps will hit still hit 100c after a couple of mins even though Vcore goes right down for some reason when running AVX loads.
Regarding fan curve, I use Icue with pump and fans set to extreme, and they reach max speed at 80c.
You mention that your cooling enables you to reach 5.2 at low voltage. I was under the impression that bclk limitations are set by the voltage required for each chip, hence the silicon lottery. You imply that your cooling has given you stability at lower voltages? I've always understood that good cooling simply allows you to run at HIGHER voltages because your cooling can handle the additional heat produced. I've never heard of good cooling reducing the power required by a given chip to hit certain speeds, meaning that better cooling might enable me to go up to 1.35, run AVX with no offset, and not fry my chip, but I can't see it giving me stability at Vcore anywhere near what you've got.
I use my rig for gaming, and haven't yet seen my chip go past 65c during gaming. Average is prob 50c, so I guess i'm nitpicking abit, I'm unlikely to ever need AVX, or even to stress my rig anywhere near Prime95 levels. I suppose I'm just trying to workout if there's anything I can do, or if I've just lost bad at the lottery.