Question Question about my 5900x settings and temperatures - Pbo limits / vcore offset

m.bsatgini

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Sep 21, 2017
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Hi I have a 5900x on a Dark Hero board, i'm using PBO + curve optimizer with those settings below and I have an EK AIO 360
On CB20 it maxes at 74c @with 4800/4600Mhz

In gaming I play I played God of war 3840x2160 No dlss All ultra except shadow on high 80/100 fps 25c ambiant
65 to 73c on cpu 70c on core RTX 3090 strix / 88 to 90 on memory temperature junction

is it all fine?

my Pbo limits are :
PPT Limit [W] [185]
TDC Limit [A] [125]
EDC Limit [A] [160]

No changes in scores in CB20 but not so much changes in temps too.
Which of those three limits has the most impact on temps and considering my other settings above, how far do you think I could lower it to lower temps and fan noise?


Also, is it a good idea and usefull to put a vcore negative offset while using curve optimiser?
Thanks
Core VID [1.310]
CCX0 Ratio [47.00]
CCX0 Ratio [46.00]
Dynamic OC Switcher [Enabled]
Current Threshold to Switch to OC Mode [90]
Calibrated Temperature Threshold to switch back [80]
LLC AUTO
PBO Limits [Manual]
Limite PPT [W] [185]
Limite PMH [A] [125]
Limite EDC [A] [160]
Precision Boost Overdrive Scalar [Manual]
Precision Boost Overdrive Scalar [1X]
Curve Optimizer [Per Core]
Curve Optimizer [Per Core]
Core 0 Curve Optimizer Sign [Negative]
Core 0 Curve Optimizer Magnitude [30]
Core 1 Curve Optimizer Sign [Negative]
Core 1 Curve Optimizer Magnitude [15]
Core 2 Curve Optimizer Sign [Negative]
Core 2 Curve Optimizer Magnitude [30]
Core 3 Curve Optimizer Sign [Negative]
Core 3 Curve Optimizer Magnitude [30]
Core 4 Curve Optimizer Sign [Negative]
Core 4 Curve Optimizer Magnitude [30]
Core 5 Curve Optimizer Sign [Negative]
Core 5 Curve Optimizer Magnitude [15]
Core 6 Curve Optimizer Sign [Negative]
Core 6 Curve Optimizer Magnitude [30]
Core 7 Curve Optimizer Sign [Negative]
Core 7 Curve Optimizer Magnitude [30]
Core 8 Curve Optimizer Sign [Negative]
Core 8 Curve Optimizer Magnitude [15]
Core 9 Curve Optimizer Sign [Negative]
Core 9 Curve Optimizer Magnitude [30]
Core 10 Curve Optimizer Sign [Negative]
Core 10 Curve Optimizer Magnitude [30]
Core 11 Curve Optimizer Sign [Negative]
Core 11 Curve Optimizer Magnitude [15]
Max CPU Boost Clock Override [100MHz]
 

m.bsatgini

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Sep 21, 2017
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I'm not "worried", i'm just trying to tweak it more and exploring the best options.

It's as it is for more than a year without issues but i would like to get it a bit cooler especially for putting fans at lower speed :)

I know those temps are fine but i was wondering about PBO limits and offset
 
I'm not "worried", I'm just trying to tweak it more and exploring the best options.
...
Something to remember about Ryzen 5000 is the boost algorithm is pretty much temperature seeking. That is, it will keep boosting until it sees temps close to 90C so long as it's still within the other boost parameters, such as PPT, TDC, EDC. So even though curve optimizer may be helping by lowering voltage at the high end of the V/F curve, alone it's not really going to result in lower temperatures even though it can result in better performance. I've noticed my 5800X is definitely pulling clocks at 80C and most severely above 85C... it's still well above base clock though, so still boosting.

C/O's effect is at the high end of the V/F curve, where the processor is hitting max clocks during light, bursty work loads (like gaming). Heavy, all-core, workloads (like rendering) drag the voltage down, and clock frequency along with it, to the low end of the V/F curve where it's effects are limited if not nulled.

With that in mind: I've read that some people have had luck actually raising voltage slightly with offsets and then raising PPT and TDC limits a bit to push the CPU harder under heavy workloads. Raising voltage acts uniformly across the V/F curve and gives a bit more margin at the high end to further reduce curve optimizer offsets. The thing is, you've already pushed almost all your cores to -30 so only a few more are left to see any reduction. That's like my CPU and I didn't see any improvement in light workloads doing that.

The idea is to get a bit more performance at the low end of the V/F curve by giving more voltage to support more aggressive PPT and TDC settings. Obviously cooling is going to be stressed much more; it has to be able to keep the CPU under 80C preferably, 85C definitely, to see anything from this.

You can try it the other way too of course: lower Vcore offset, raise the C/O offsets (or let the -30 ones ride, effectively lowering them even more) while pushing out PPT and TDC to increase performance. Mine went unstable too quickly when I tried that to see any good effects under Cinebench testing, which was where I most wanted to see improvement.

Cooling could be limiting my CPU but everything here very much depends on your specific silicon and how your motherboard's BIOS has been preset by the mfr. That means results aren't universal so you can't copy what others have done and expect similar results. You have to experiment with your system to see how it responds to changes. Just keep in mind the principles of what's going on so you can make sense of results and give you ideas on what changes to make next.
 
Last edited:
Jul 7, 2022
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I'm not "worried", i'm just trying to tweak it more and exploring the best options.

It's as it is for more than a year without issues but i would like to get it a bit cooler especially for putting fans at lower speed :)

I know those temps are fine but i was wondering about PBO limits and offset
Okay well I will go over the 3 parameters and let you tweak them (that’s half the fun anyway) EDC is electric design current, this is the amperage limit for very short term transient current demand, a good way of looking at EDC is it allows a single core or multiple cores to boost to maximum for a single second or so where temps won’t get out of hand so I wouldn’t worry about EDC. TDC is thermal design current and determines the maximum current flow allowed for long durations. This will have an effect on sustained temps under load so you can play around with this (like reducing by 5 amps, test, and repeat to see how much this setting affects your temps. PPT is package power target is total power allowed to be fed into your CPU. This (if I remember correctly from my tweaking session) has the most significant effect on your sustained load temperatures because setting the total power limit will also limit TDC because power = voltage * current and if you set the power limit low enough then, with stock voltage, the only thing the cpu can do to stay within the PPT is to prevent maximum set TDC from occurring.
I encourage you to mess with the settings and figure out the characteristics and find the best balance. However, absolutely DO NOT decrease voltage as ryzen 5000 has a new stability safety mechanism known as clock stretching where if you set a lower voltage then your computer won’t crash but it will get slower because the CPU is stretching its clock speed to maintain stability (you will be able to check for this by looking at ryzen master while doing something like a cinebench run with the PBO and CO settings you have now, then lower the voltage and repeat. Ryzen master will tell you that your cpu is running at the same clock speed as before but your cinebench score will be lower because clock stretching limits the amount of work your cpu can get done per clock cycle to remain stable.)

Good luck and have fun! If you have any more questions don’t hesitate to ask and please update us on how your tweaking turned out.
 

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