Question i9 12900K Overclocking at 5.1 [Questions]

Mar 30, 2022
Hi all, I have got a couple of questions on overclocking my i9 12900K.
  • Set P-Core to 5100 MHz
  • Set E-Core to 4100 MHz
  • CPU ratio when running AVX | Set to 0
  • Ring Ratio | Left on Auto
  • CPU core voltage set to 1.30
  • C1E Support | Disabled
  • EIST / Inter Turbo Boost | Disabled
Windows boots fine and I'm going to start stress testing. The issue I'm seeing is that HWinfo or HWMonitor report the following:
  • bus clock shows as 98.8 ?! Why ?!
  • P-core maxes at 5087 MHz > never reaches the multiplier value: 5100 MHz
  • E-core maxes at 4090 MHz > never reached the multiplier value: 4100 MHz
Also this is important. I ran Cinebench 23 really quick and after a few minutes noticed a huge drop to 800 Mhz on many cores?
Why? I understand that it might be related to throttling, but how do I avoid this drop from happening?
Note: Also ran Prime95 for a few minutes and this DOESN'T happen in when Prime95 is running.

Full PC Specs:

CASE: Thermaltake View 51
CPU: Intel® Core™ i9-12900K Processor
MEMORY: Corsair Vengeance RGB Pro 32GB (2x16GB) DDR4 3200 (PC4-25600) C16
POWER SUPPLY: 1050 Watts - Enermax EDT1050EWT MaxTytan Series 80 PLUS Titanium certified Full Modular Active PFC Power Supply
Cooler: Thermaltake Water 3.0 360mm ARGB Sync Edition high performance CPU waterblock Cooling System w/ Copper Cold Plate
Storage: (2 drives 1TB each) - 2 X 1TB WD Blue SN550 NVMe M.2 SSD + 3TB Barracuda HDD (Totaling 5 TB drive space on this PC) OS: Windows 11 Home (64-bit Edition)
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Hi the bus and clock speeds will rarely be exactly at 100, 5100, and 4100 but always very close so those numbers are fine. As to the Cinebench drop off, it would be good to know what temps you were hitting under load for Cinebench R23....

Also is this an all core 5.1GHz?
Also what is your Cinebench score during the multi-core test?
Also I would drop the e-cores down to a max for 4Ghz as not really required and just add to stability and heat issues when at max ramp for the P-Cores.
I run a ASUS motherboard so settings are different to the MSI side but for MSI motherboards, remove all power limits, these settings are listed in the UEFI as the Long Duration Power Limit, Short Duration Power Limit, and the CPU Current Limit. You should enter the first two values as 4096W, and the latter value should be set to 512A. Finally, set the Long Duration Maintained value to the longest allowed (128 seconds). '

You have probably seen this on the Toms Website but this was for an MSI board.
What is your purpose in overclocking your 12900k?

Normally, gamers will do better by letting the turbo mechanism boost to higher numbers than you can get with an all core overclock.
Overclocking is more appropriate for batch apps that can fully load all cores.

If your performance drops, then, I think you are correct that you have throttled.
Run HWmonitor.
It will show the current, minimum, and max temperatures , clocks...
If your minimum is 10-15c. over ambient, your cooler is mounted well and functioning.
If you see 100c on any core, it likely has throttled.

Where is your radiator mounted, and does the radiator use outside fresh air or inside air?
Mounting an aio is a catch 22 thing.
If you mount the radiator to take in fresh outside air, your cpu will be cooled best.
But, then the hot radiator exhaust will be used to cool your motherboard vrm's as well as the GTX3090.
OTOH, if you mount the radiator to exhaust the hot air, your motherboard and graphics card will be cooled better at the expense of less than optimum cpu cooling.
In regards to your overclock, what is your overall goals with regards to speed? I've stepped away from traditional all core OCs with this generation, and set speeds to a per core usage OC. The newer CB23 is also using AVX instructions, and AOIs in general are going to struggle with temps on 12900ks when OCing.