Question CPU core clock decreases when running games even though overclock is stable.

Jun 16, 2022
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I've been recently running into issues where the instant I boot up games (AC Odyssey and League of Legends) my core clock will drop from 5000 MHz to 4700 MHz. This decreased core clock will remain until I restart my system. In HWinfo it tells me that the core power limit has been exceeded, however, this warning never popped up when I ran stability tests in Cinebench r23 and Prime95. I would assume that those benchmarking tools would be more power-intensive than opening League of Legends.
Here are my main overclock settings:
  • CPU ratio: 50
  • Avx offset: -1
  • Ring ratio: 47
  • CPU core voltage mode: override mode
  • CPU core voltage: 1.35
  • LLC mode 3
  • PL1: 4096
  • PL2 4096
My Cinebench r23 score comes out to ~9800 and the overclock was stable through 3 hours of Prime 95 small FFT avx off. Core temps are around 36-40 idle and 75-80 under load.
I'd appreciate any help in finding the root cause of the issue. Thanks.
My system specs:
  • CPU: i7 9700k
  • CPU Cooler: Dark Rock Pro 4
  • Ram: Corsair Vengeance LPX 16GB DDR4 3200 MHz
  • GPU: RTX 3070
  • Motherboard: MSI MPG Z390 Gaming Edge AC
  • Power Supply: Corsair RM 850x
  • Case: Fractal Torrent
I have also tried downclocking my CPU to 4800 MHz, but the core clock will still drop down to 4700 MHz when opening those games.
 
Well the only thing you have limited is Vcore, so I would try that first, not that 1.35 shouldn't be more than enough though.
Also is it just coincidence that the CPU downclocks to the same clocks your ring bus is set to? Can you try lowering the ring bus to see if the CPU will downclock to that new setting?
 

Karadjgne

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This decreased core clock will remain until I restart my syste
That's the concern, not the drop itself. 4.9GHz is 1,2,3 cores, 4.7GHz is 4,5 and 4.6GHz is 6,7,8 cores. But you seem to have OC'd the cpu by setting a 5.0GHz, without supporting clocks and soon as you use it, the cpu is objecting.

Ring ratio is the cpu cache speed and should be equal to the cpu ratio. Set ring ratio for 50 if keeping the 5.0GHz cpu ratio.
 
@Nestakofi
Are you running MSI Dragon Center or any similar MSI control software? Some versions of this software had a bug where it would incorrectly set the turbo power limits. If you have this program installed, uninstall it.

Another possible problem is that the largest value that can be stored in the PL1 and PL2 power limit register is 4095.875 W. If the bios or any software tries to write 4096W to that register, the register will overflow and it will contain a value of 0 Watts. To avoid this problem, never set the PL1 or PL2 power limit registers in the BIOS higher than 4095W.

Are you using the latest available BIOS? Some of these bugs have been fixed.

Try running ThrottleStop 9.4.6.
https://www.techpowerup.com/download/techpowerup-throttlestop/

Post screenshots of the main window, the TPL and the FIVR windows, preferably when your computer is being limited to the 47 multiplier. You can also open up the Limit Reasons window to watch for any throttling flags turning red under the CORE column. Completely exit HWiNFO when testing with ThrottleStop.

Post some screenshots and turn on the ThrottleStop Log File option if you are still having problems. When finished testing, exit ThrottleStop so it can finalize the log file. It will be in your ThrottleStop / Logs folder. You can copy and paste the data to www.pastebin.com and then post a link here.

Leave the ring ratio at 47. Hardly anyone ever sets the core and the ring to the same speed. It takes way too much voltage to do this reliably. For many Intel CPUs, it is impossible to get this stable. All this does is it creates way too much heat for very little performance gain.

In the BIOS it is best to enable Ring Down Bin. This feature always keeps the CPU ring / cache 300 MHz less than the CPU core. Ring Down Bin helps to prevent instability. If the core ever needs to slow down, the ring will automatically slow down too.

This power limit problem seems to be triggered for some games when the Nvidia GPU is active. That is why things that do not use the Nvidia GPU such as Cinebench R23 will run at full speed without any problems but some games will throttle and slow down.
 
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