Question Undervolting and PBO

kurdtnz

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Feb 24, 2020
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I seem to be having some kind of problem getting undervolting my cpu ,(similar to this method Ryzen 5000 Undervolting with PBO2 – Absolutely Worth Doing - YouTube ) and engaging with PBO with Ryzen master,they dont seem to be playing well together but work fine when using individually. If I touch nothing in BIOS and run PBO with Ryzen Master, it does it's thing and boosts all my cores. Then if i turn off RM and make similar changes in my BIOS (from that video above) It also runs really well and boosts all cores even higher and single threaded loads run really well at 4.8Ghz. However, when I keep the undervolt settings in BIOS then enable Ryzen Master and PBO, the cores drop speed than if I was running both individually. During the undervolt changes in BIOS, I have been setting the 'max cpu boost overdrive' to 150mhz which runs stable with my system but I have noticed when PBO is enabled in RM, it changes it back to zero in BIOS. Am I doing something wrong?

5600X
x570 i aorus pro wifi
RTX 2060
2x8 (16GB) 3200 RAM
650w seasonic psu
 
I seem to be having some kind of problem getting undervolting my cpu ,(similar to this method Ryzen 5000 Undervolting with PBO2 – Absolutely Worth Doing - YouTube ) and engaging with PBO with Ryzen master,they dont seem to be playing well together but work fine when using individually. If I touch nothing in BIOS and run PBO with Ryzen Master, it does it's thing and boosts all my cores. Then if i turn off RM and make similar changes in my BIOS (from that video above) It also runs really well and boosts all cores even higher and single threaded loads run really well at 4.8Ghz. However, when I keep the undervolt settings in BIOS then enable Ryzen Master and PBO, the cores drop speed than if I was running both individually. During the undervolt changes in BIOS, I have been setting the 'max cpu boost overdrive' to 150mhz which runs stable with my system but I have noticed when PBO is enabled in RM, it changes it back to zero in BIOS. Am I doing something wrong?

5600X
x570 i aorus pro wifi
RTX 2060
2x8 (16GB) 3200 RAM
650w seasonic psu
Use either BIOS or Ryzenmaster to make changes for PBO, never both simultaneously or you get odd behaviors which is probably you're seeing. BIOS is usually preferred since settings are applied at every boot-up. Ryzenmaster was intended for extreme overclockers.

Undervolting should be done in small steps after settling on preferred PBO settings, using offset adjustment never fixed. Be sure to test for both multi- and single- thread performance as well as stability when undervolting.

Also don't expect results similar to what others might get. Not only is there the 'silicon lottery' to allow for but some motherboard mfr's intentionally mis-report power consumption to the processor (and to monitoring utilities) in order to gain performance advantage. And they don't do it on all their motherboard BIOS' either.
 
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kurdtnz

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Use either BIOS or Ryzenmaster to make changes for PBO, never both simultaneously or you get odd behaviors which is probably you're seeing. BIOS is usually preferred since settings are applied at every boot-up. Ryzenmaster was intended for extreme overclockers.

Undervolting should be done in small steps after settling on preferred PBO settings, using offset adjustment never fixed. Be sure to test for both multi- and single- thread performance as well as stability when undervolting.

Also don't expect results similar to what others might get. Not only is there the 'silicon lottery' to allow for but some motherboard mfr's intentionally mis-report power consumption to the processor (and to monitoring utilities) in order to gain performance advantage. And they don't do it on all their motherboard BIOS' either.
To be honest, after playing around with it, even though I can get slightly faster multicore speeds with PBO2/undervolting, it's way more stable for me using the latest CTR. Games keep crashing after awhile with PBO2/undervolting but Im still getting faster single core speeds but slower multicore speeds,(only talking 50mhz) with CTR and have had no crashes. (plus cooler temps.) I could probably get PBO2 more stable if I spent quite awhile adjusting each core individually but with a relatively new comer to OC'ing/undervolting like me, it's easier just to use CTR.
 
... faster single core speeds but slower multicore speeds,(only talking 50mhz) with CTR ...
If I've discovered one thing with my 3rd gen CPU it's that I can't rely on looking at core clocks alone to assess processor performance with any settings that leave clocks in AUTO, e.g., using PBO. I'm pretty sure it's going to be the same with any 4th gen CPU too. The boosting is just way to dynamic...up and back down constantly up to 100 times a second. Even looking at average core clocks is pointless as utilities miss way to many of the extremes with the (relatively) long polling times I have to use to not affect results.

I've come to rely exclusively on performance testing to determine relative merits of a setting. Cinebench benchmark runs, both multi and single- thread, the only way to do that.

And use the long, 10 minute, run to check cooling performance and 30 minute for stability too. It's actually nice to see the performance over that long run going down a little bit as I know the processor is protecting itself. In order to compare I'll use the same test for any fixed overclock settings too, but performance (clocks) can't be pulled back of course. So it just keeps on heating up until it crashes...or worse...when cooling isn't enough.
 
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Karadjgne

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Not a big fan of RM personally, I find it a little flaky on my pc.
So far I've found ClockTuner2 (guru3d.com) to be just the ticket I want. Fine tunes VID and clocks to get best actual stable performance without affecting idle. At (my setting) 18% loads I get a mild OC, so take full advantage of higher VID per CCX and higher boosts, upto 54% loads which have a higher tighter OC for maximum performance vs temps vs voltages.

Overall affect is a good balance of OC without a bios set hard OC and a minor loss of performance for a 20°C drop in temps.
 
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victortsoi

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Not a big fan of RM personally, I find it a little flaky on my pc.
So far I've found ClockTuner2 (guru3d.com) to be just the ticket I want. Fine tunes VID and clocks to get best actual stable performance without affecting idle. At (my setting) 18% loads I get a mild OC, so take full advantage of higher VID per CCX and higher boosts, upto 54% loads which have a higher tighter OC for maximum performance vs temps vs voltages.

Overall affect is a good balance of OC without a bios set hard OC and a minor loss of performance for a 20°C drop in temps.

This is very interesting, are you saying that CTR is to be used instead of RM or bios tweaking?
 

kurdtnz

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This is very interesting, are you saying that CTR is to be used instead of RM or bios tweaking?
For someone like me who is still not 100% comfortable or experienced enough playing around with BIOS settings, CTR is ideal. With my 5600X, Im getting a better all core OC and single threaded boosts of 4.8Ghz on three cores with lower voltages and cooler temps. I do subscribe to Yuri's Patreon page though so get to use the pre-release versions of CTR.
 
This is very interesting, are you saying that CTR is to be used instead of RM or bios tweaking?
CTR helps to find a fixed 'overclock' through some iterative testing. It's biased to look for one at a safe voltage. Once found it can apply it using Ryzenmaster's service so you still need to have Ryzenmaster installed.

At least, that's how I recalled it. The overclock it found for my system actually degraded gaming performance and only barely beat all-core stock performance. When I tried to push it with settings that would use less safe voltages it would just BSOD or re-start in the middle of testing. My PBO overclock handily exceeds all-core stock performance and slightly beats gaming performance.
 

victortsoi

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Im really struggling- im getting a 5900x and dont want to go crazy, want to get the most out of the chip and just dont know what to do to achieve that. PBO2 in ryzenmaster/bios?
 

victortsoi

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CTR helps to find a fixed 'overclock' through some iterative testing. It's biased to look for one at a safe voltage. Once found it can apply it using Ryzenmaster's service so you still need to have Ryzenmaster installed.

At least, that's how I recalled it. The overclock it found for my system actually degraded gaming performance and only barely beat all-core stock performance. When I tried to push it with settings that would use less safe voltages it would just BSOD or re-start in the middle of testing. My PBO overclock handily exceeds all-core stock performance and slightly beats gaming performance.
SO what would you have done differently? just turn on pbo2 and leave it alone?
 
SO what would you have done differently? just turn on pbo2 and leave it alone?
I'm not sure what your baseline is to differ from but I enable PBO, extend the limits (ppt 330, tdc and edc 230 to start), set a PBO Scalar of 10X, additional boost clock of +250Mhz. You have to have very good cooling for this as PBO (especially with a scalar of 10x) does make the CPU run a lot hotter so if it's not cooled the algorithm just pulls back on clocks and you think it's not working.

But then I've a B450 motherboard and a 3700X CPU. You'll have a 5900X and a B550 or X570 board. 5000 CPU's are very much different in how they handle PBO so that may not be good for you. I suppose I'd start with the video that OP posted...this one here.

I'm not a fan of fixed overclocking on Ryzen processors because it more often than not results in hurting the light threaded performance that's more important for gaming. But if you want to have an overclock for rendering or transcoding it might be helpful.
 
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Karadjgne

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Safe voltages is not really a thing for Ryzens the way it is for Intels. Intels are not a dynamic cpu as such, so setting a single voltage that covers all cores at any use is fine, even preferred in OC cases. But Ryzens differ, you'll see voltages of upto 1.5v used for a single core bump, which lowers amperage needs for that core, but bump that upto multiple cores and you'll see much lower voltages in the 1.2-1.3v range. So setting a fixed voltage of 1.3v is going to hurt single core performance but could also be too much for all core use.

So what is safe? Many early Ryzen adopters who did OC thinking they were safe, burned out cpus in less than 6 months, by applying a roughly 1.325v fixed.

That's one reason I prefer CT2, it doesn't change or set vcore (SVI2) use, it limits VID instead. That changes what the cpu Can use upto, not setting what the cpu Will use always. It allows the Ryzen to decide for itself what it needs in reality, not what it can get away with demanding, used or not.

PBO changes power limits. If you are pushing the 90A power limit and that's forcing the Ryzen to throttle back to stay inside the limit, then PBO is going to set the cpu free to go beyond that 90A. Doesn't mean it's going to Use that amount set. The MSI Godlike and Gigabyte Master can set that limit to 1000A. There isn't a Ryzen made that'll ever come remotely close, those boards are set to erase any possible limitations, even using LN2.

So use of PBO isn't going to give you any further performance as such, it just extends the power limits so that they don't become a limiting factor in the performance desired. Factory PBO just sets the limits at AMD set limits, which raises the range of what the Ryzen deems as tolerable. PBO 1 or PBO 2 etc don't use AMD set limits, but motherboard vendor limits.

If you are not hitting 100% of the power limits, raising them by bios or Ryzen Master isn't going to affect performance at all.

But a lot depends on how you view performance, a personal opinion. For Ryzens, they'd prefer you to get lower fps for an hour long gaming session and stay inside its deemed safe limits, than to get the extra few fps by pushing limits and possibly doing irreparable damage and bsod after 10 minutes. Intels will give you want you want now and deal with the consequences later.

A Ryzen will do what it has to to keep you out of 90ish °C ranges, an Intel will happily let the cpu sit in that 90°C + range, it's on you to supply the cooling necessary to lower it.
 
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tennis2

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For Ryzens, they'd prefer you to get lower fps for an hour long gaming session and stay inside its deemed safe limits, than to get the extra few fps by pushing limits and possibly doing irreparable damage and bsod after 10 minutes. Intels will give you want you want now and deal with the consequences later.

A Ryzen will do what it has to to keep you out of 90ish °C ranges, an Intel will happily let the cpu sit in that 90°C + range, it's on you to supply the cooling necessary to lower it.
Bit of an exaggeration against Intel here.
 

Karadjgne

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Not really. You get nothing until you get right at tjmax, it'll go all out at whatever its setting is at, regardless of temps until it hits tjmax, or right very close.

Somebody pushing 95°C wouldn't have a clue, performance would be the same as at 65°C. Especially in a prebuilt like a Dell with its pathetic cooling and maxed out fan at almost any decent load.

My wife can run Office like a champ, she has no issues with Working on a pc, but when it comes to hardware and working On a pc, she's absolutely clueless, would have zero thoughts to look at temps etc.

Much happier having a Ryzen and her saying it's just not as snappy as it used to be than her telling me it keeps shutting off for no reason when I'm not home.
 

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