PC Processors

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Bought my 7800X3D at launch

Wondering if cinebench temps under multicore load, reaching 89 is normal with a noctua NHD15 going full blast

Plus gaming (cossacks 3) brings temps up to 83degrees

Recently i wanted to capped the temps at 85 instead of 89 but am considering capping it at 80 so i wanted to know if that is something that is worthwhile doing aswell.

[toddd240]

I have a 7950x3D and with a Ryujin III 360 on silent I am getting about 83 on Cinebench with OCing the CPU. I have also lowered the power consumption on it a bit in the bios. I don't think you necessarily need to lower the TJMAX on it as it is designed to throttle at 89. You can probably safely lower the power consumption on it in the bios if you are not OCing it. That might squeeze out a couple more degrees.

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with negative pbo all cores? or lower voltage?

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Followup question. Just lowered the PPT to 80Watts and put a thermal limit to 80Cs

Got better scores on cinebench but i have 1 question. What is the difference between lowering only the ppt or setting a thermall limit? Or doing both at the same time (what im currently doing)?
Is there any difference in terms of performance?

[toddd240]

I’d leave the voltage setting alone and use the curve. You can dial per core if you want to spend the time doing it.

Liwering the ppt will limit the voltage to the socket. Lower volts, less power available, less heat, possible instability. 

putting a thermal limit will just throttle the cpu quicker regardless of volts

the point of lowering the curve through pbo is so you can avoid the cpu using unnecessary volts for the same amount of computing power, thus reaching your cpus maximum capability without throttling.

you can keep the tjmax default and start lowering the curve on a per core basis to find stability with getting the most of your cpu before it throttles. 

if you lower the cpu threshold at the same time as lowering power, you are lowering heat and still may not hit your cpus maximum capability. You could do that if your goal is to just lower temps without getting more production from your cpu.

[Continente]

Ive managed stability in r23 and my Unreal 5.3 rendering with negative 40 on 6 of my cores and on the best cores i managed negative 30. Has been running for 4 hours without any instability. I also got the ppt to 80 so temps never go above 80Cs. Constantly reaching 5050Mhz with easy and r23 score improved from 17900 to 18850.
If i do not use ppt then with r23 my temps, even with curve optimizer, stay stuck at 89.

If i do not lower the ppt and try with the curve optimizer values i have now, instability ensues and the system crashes. Any reason for this?

[toddd240]

Just guessing, but your ppt may be holding the CPU back from pushing too far so it avoids instability. 

If you are happy with the results from lowering the max to 80, and it's stable, you should stick with it.

Not all CPUs are created equal. But it seems you are able to get the max standard boost while lowering CPU temps on air at the same time. If you are trying to overclock it, that cpu probably will need a healthy AIO system to lower temps.