How to limit vcore/clock Ryzen 5900X

[Tuvoc]

Hi,

My 5900X tries to maximise performance by significantly increasing vcore to attain ever high clocks. Sometimes that is welcome, but other times not. It generates a lot more heat and subsequently noise from the cooling solution. We know the law of diminishing returns, and for at least some of the time I want to achieve a better compromise.

So mostly I'm running 12 threads, and the clock sits at 4.5GHz with vcore at about 1.3v. I'd like to limit the maximum clock to 4GHz and with that would come less vcore and less heat. How much less vcore that would be I don't know. Ideally I'd like to use Ryzen Master for this so that I can toggle it back to full performance when needed. But I can't see how to do this.

I did try reducing the TDC and that did bring the clock speed down, and the vcore to 1.1v (and 20C less heat) on the 12 threads. Great I thought, but Prime95 immediately failed on a couple of cores so it seems the motherboard/CPU were not intelligent enough to work out the right balance.

Motherboard is MSI B550M Mag Mortar Wifi. If the best way to do this is through the BIOS then that is what I'll do.

Any suggestions for me much appreciated. Happy new year all.

 

[Tuvoc]

Thanks - perhaps just changing the TDC value by itself was not the right approach. I'll further experiment with all three values, maybe they need to be reduced proportionately. Or else maybe PPT by itself might achieve it.

 

[Tuvoc]

Looks like simply lowering PPT is the answer.

 

[Tuvoc]

Ppt is the way to go. However do try setting pbo to manual and leave scalar at 1x or auto. Can also try curve optimization of -5 across all cores.
If pbo is on auto it tries to auto oc and uses silly high voltages.

My 5600x is on stock clocks but ruining 105w ppt which raises its all core boost clocks a fair bit. Overnight video encoding going on and its mostly at all core 4.52ghz and 83c temps. In prime95 clocks are lower around 4.3ghz. however in prime95 using 8 threads it will boost to 4.6ghz and hold. Temps at 82c.

Thanks, coincidentally the last few hours I did set PPT to 105w and that seems t be doing the job very nicely. It is running around 4.1GHz and 1.18V and I'm sure that is rock-solid. Good reduction in temps and noise compared to letting it run up to 4.5GHz at 1.3v.

@Joxeon, Yes I've named a profile for this reduced setting, and if I want maximum performance again there is a reset option to click which puts things back to stock

Thanks for the help guys.

 

[Tuvoc]

Does it still boost up to higher clocks on lighter loads?

Me ? Yes, it still boosts up to 4.9 under 1 or 2 cores, at silly high voltages, because it can do that and still stay within the 105w TDP. It is not very often that the machine is in that situation.

 

[Tuvoc]

I dont like the silly high volts dont sit right with me. Maybe you can set a negative frequency offset of -200mhz so it boosts to 4.7ghz insted and it may max voltage at around 1.35v to get there?
Dunno if thats possible would need to experiment some.

Yes I don't like it either, although it is by design. its no different from my Intel 10900 actually, which boosts to 5.2GHz on 1 core at around 1.43v (although typically 5.0GHz with less vcore). It seems more tolerable on that though, the cooling system doesn't react to it very much at all, maybe it is reading a different sensor perhaps. The overall socket temp surely can't be increasing much. On the Ryzen though when 1 core boosts like that the fans ramp up as if the entire CPU was fully loaded.