Undervolting 13900

[Bufaritza]

Hello,

 

I have an issue that is driving me a bit crazy. So my current specs are as follows:

 

-i9 13900(non k), with arctic mx-6 paste cooled by a Dark Rock Pro 4.

- MSI Z790-P Wifi

-2x16GB DDR5 6400MHZ

 

If I leave everything at stock, which means 4096W thermal limit, 512A and all the other nonsense, I can reach the usual top scores in cinebench and cpu-z bench, but with the big caveat of HEAT. Like 100C thermal throttle heat. 

Hwinfo is reporting ridiculous 1.5+ core VID's, which I believe is insane.

Now, The first thing I did was set everything to stock PL1 and PL2, meaning 65W, respectively 219W. In order to "trick" pl1, I also tried variations of setting PL1=PL2, so 219W=219W or other values.

No mather what combination I use, If I run Cinebench or cpu-z, I get very low scores. As an example, CPU-Z is reporting around 6300 points, when it should be around 15k. Here is the kicker: If I wait the full PL2 56 seconds tau time, while the CPU consumes around roughly 125 W, it then goes down to 65W or whatever value I put PL1 and the scores start INCREASING, until they hit the wall for that wattage.

Reported voltage and cpu frequencies also drop in PL1 mode. But in PL2, the CPU is reporting full 5.3ghz on P cores and 4.2ghz on E cores, and yet the scores are lower. 

I also tried overriding the cpu voltage to 1.2, which is reported correctly in cpu-z, but it is all over the place in hwinfo, like 1.35-1.47, which I believe depends on the LLC and Lite I choose for the CPU.

 

Can someone please help me understand why my CPU is behaving this way? It doesnt seem to affect any gaming benchmarks that I tried, but I am genuinelly worried that there is something broken with my motherboard. I have tried numerous undervolt videos and threads, and yet I cant reproduce the results there.

[RONOTHAN##]

42 minutes ago, Bufaritza said:

I also tried overriding the cpu voltage to 1.2, which is reported correctly in cpu-z, but it is all over the place in hwinfo, like 1.35-1.47, which I believe depends on the LLC and Lite I choose for the CPU

HWInfo at the top reports VID, which is very different than the voltage actually making its way to the CPU. VID is the voltage the CPU is requesting, VCore is the voltage that is making it to the silicon. VID doesn't care what the LLC or Lite mode you have set, while VCore does. You generally don't want to try setting up a manual voltage for the non-K SKUs (excluding 12th gen if you have one of the handful of boards that supports overclocking), as a lot of the time you run into clock stretching, where scores fall even though clock speeds still report high. 

 

As for why your power limits are causing weird performance regressions, this is almost certainly a BIOS bug. Try a different BIOS revision or two to see if that makes any difference. 

[unclewebb]

5 hours ago, Bufaritza said:

I get very low scores

Intel has a new broken feature called Undervolt Protection. This can cut benchmark scores in half. Use HWiNFO to see if UVP is enabled. It sure seems like it.

 

You can also run ThrottleStop. Post screenshots of the TPL and FIVR windows. It will show in the FIVR window if Undervolt Protection is enabled. 

 

The BIOS might not be setting the turbo power limits correctly. The ThrottleStop TPL window lets you see what these limits are set to and allows you to make adjustments in real time.

[Bufaritza]

On 7/7/2023 at 5:15 AM, unclewebb said:

Intel has a new broken feature called Undervolt Protection. This can cut benchmark scores in half. Use HWiNFO to see if UVP is enabled. It sure seems like it.

 

You can also run ThrottleStop. Post screenshots of the TPL and FIVR windows. It will show in the FIVR window if Undervolt Protection is enabled. 

 

The BIOS might not be setting the turbo power limits correctly. The ThrottleStop TPL window lets you see what these limits are set to and allows you to make adjustments in real time.

Below the TPL and FIVR windows. I could not find the disable UVP setting in the bios. I have the latest one. Should I downgrade bios by bios to see if it was available in previous ones?

These are default values btw. Everything works like a charm, but it gives it ridiculous amounts of voltage.

 

[unclewebb]

8 hours ago, Bufaritza said:

ridiculous amounts of voltage

I just remembered. Intel removed software CPU voltage control from the 13th Gen non K CPUs. That is why ThrottleStop shows Not Available at the top middle of the FIVR window. The default voltage is sky high. This creates a lot of excessive heat. You can no longer use ThrottleStop or Intel XTU to control this. 

 

If you try to reduce the voltage in the BIOS, this likely triggers the dumb Undervolt Protection feature within the CPU. This can drop your Cinebench scores in half. Not sure who at Intel thinks this new feature is a good idea.

 

The non K CPUs used to be a good choice for users not interested in overclocking. I cannot recommend non K CPUs anymore. The K series should give you full control over the voltage and heat. The non K series do not.

 

The non K CPUs are usually the second rate CPUs that were not good enough to be K series CPUs. They tend to need more voltage to run stable. The default voltage table programmed into them might be higher compared to a similar K series CPU. Another reason to avoid non K CPUs. 

[Bufaritza]

On 7/9/2023 at 5:56 PM, unclewebb said:

I just remembered. Intel removed software CPU voltage control from the 13th Gen non K CPUs. That is why ThrottleStop shows Not Available at the top middle of the FIVR window. The default voltage is sky high. This creates a lot of excessive heat. You can no longer use ThrottleStop or Intel XTU to control this. 

 

If you try to reduce the voltage in the BIOS, this likely triggers the dumb Undervolt Protection feature within the CPU. This can drop your Cinebench scores in half. Not sure who at Intel thinks this new feature is a good idea.

 

The non K CPUs used to be a good choice for users not interested in overclocking. I cannot recommend non K CPUs anymore. The K series should give you full control over the voltage and heat. The non K series do not.

 

The non K CPUs are usually the second rate CPUs that were not good enough to be K series CPUs. They tend to need more voltage to run stable. The default voltage table programmed into them might be higher compared to a similar K series CPU. Another reason to avoid non K CPUs. 

So there is nothing I can do from what I understand. I chose the 13900 non K, because I rely on air to cool the CPU, so 13900k was never going to be an option. 

That, and I also got a good deal on it and said I will UV it to get less heat out of it. My last question is how much does this affect actual performance? I understand there are issues with cinebench and syntethics, but is there any other drawback?

I know gaming is just one area, but I haven't really noticed any degradation there. Really surprised how Intel dropped the ball so hard on this one.