3900x PBO.

[Scottx125]

So I'm quickly writing this thread before I go to work. I've been trying for months on and off to get PBO to work to see how well it performs. However throughout all my tests I've found that all core load generally starts at 4.1ghz and goes down to 4.05ghz. Max single core speed is around 4.3Ghz. The infuriating part about this is the fact that temps are still low. On all core i'm hovering between high 60's and low 70's and on single barely 55 degrees. So there's plenty of thermal head room but for some reason the cores just won't go any higher.

I've tried numerous settings turning core performance mode on, under volt off-set by 0.1 on the CPU, setting load line calibration, changing various PBO settings (tried setting the PBO power settings to 1000 and the clock was stuck at 3775Mhz) and none seem to boost it higher. The afore mentioned boost clocks were with 395(PPT)/255(TDC)/255(EDC)(Max I can go before it sticks to 3775Mhz, none of these were close to being reached 100%). Higher scalar setting didn't seem to do anything and core OC offset was +200Mhz. Mobo and chipset are fully updated.

Relevant specs:
CPU: 3900X.
Mobo: Crosshair VIII Hero.

Idk if I'm missing something or doing something wrong but I've seen tons of people being able to get their PBO to boost single cores up to 4.6Ghz. I've had to resort to manually OCing to just under 4.4Ghz all core at 1.3625v.

 

[Panos]

So I'm quickly writing this thread before I go to work. I've been trying for months on and off to get PBO to work to see how well it performs. However throughout all my tests I've found that all core load generally starts at 4.1ghz and goes down to 4.05ghz. Max single core speed is around 4.3Ghz. The infuriating part about this is the fact that temps are still low. On all core i'm hovering between high 60's and low 70's and on single barely 55 degrees. So there's plenty of thermal head room but for some reason the cores just won't go any higher.

I've tried numerous settings turning core performance mode on, under volt off-set by 0.1 on the CPU, setting load line calibration, changing various PBO settings (tried setting the PBO power settings to 1000 and the clock was stuck at 3775Mhz) and none seem to boost it higher. The afore mentioned boost clocks were with 395(PPT)/255(TDC)/255(EDC)(Max I can go before it sticks to 3775Mhz, none of these were close to being reached 100%). Higher scalar setting didn't seem to do anything and core OC offset was +200Mhz. Mobo and chipset are fully updated.

Relevant specs:
CPU: 3900X.
Mobo: Crosshair VIII Hero.

Idk if I'm missing something or doing something wrong but I've seen tons of people being able to get their PBO to boost single cores up to 4.6Ghz. I've had to resort to manually OCing to just under 4.4Ghz all core at 1.3625v.

I have written time an again in various discussions how to configure the 3900X for light loads. Which means 1-2 cores hit 4600+ (on D15 at least) and the rest on light loads are hovering between 4400-4550. If you try to push CB20 then ofc this is not light load and the CPU will throttle down to reduce power. Why? Because on light loads AMD has said 1.5v is fine, but on heavy loads (all core 100%) anything over 1.27v would damage the worst dies.

Have a look here. I have PBO off as I am using again 1usmus v1.1 these days but have activated XFR and everything else he advices. Also make sure you have uninstalled Ryzen Master from your system and you have flashed the BIOS after you done so.

https://forums.overclockers.co.uk/posts/33266474/

 

[Scottx125]

Thanks I'll take a look at this when I get back from work. Problem with this is there's so many conflicting discussions on how to actually get PBO to work properly.

 

[Panos]

Thanks I'll take a look at this when I get back from work. Problem with this is there's so many conflicting discussions on how to actually get PBO to work properly.

I do not use PBO. I use XFR and the 1usmus or Community_v3 powerplans succesfully since November.

 

[Minstadave]

I have written time an again in various discussions how to configure the 3900X for light loads. Which means 1-2 cores hit 4600+ (on D15 at least) and the rest on light loads are hovering between 4400-4550. If you try to push CB20 then ofc this is not light load and the CPU will throttle down to reduce power. Why? Because on light loads AMD has said 1.5v is fine, but on heavy loads (all core 100%) anything over 1.27v would damage the worst dies.

Have a look here. I have PBO off as I am using again 1usmus v1.1 these days but have activated XFR and everything else he advices. Also make sure you have uninstalled Ryzen Master from your system and you have flashed the BIOS after you done so.

https://forums.overclockers.co.uk/posts/33266474/

I tried your settings and couldn't get anywhere near your results, I wonder if there is an element of silicon lottery.

 

[Panos]

I tried your settings and couldn't get anywhere near your results, I wonder if there is an element of silicon lottery.

With 1usmus need to have PBO OFF to work, otherwise on Auto/Off if you want Community_v3. Also requires latest chipset.

And all the settings those 2 powerplans ask also. (CPPC etc).

Have a look here where to find some of the settings, all BIOS should be the same.

https://forums.overclockers.co.uk/posts/33133217/

 

[Brizzles]

I tried your settings and couldn't get anywhere near your results, I wonder if there is an element of silicon lottery.

Auto/Off if you want Community_v3. Also requires latest chipset.

And all the settings those 2 powerplans ask also. (CPPC etc).

Did some tests with Panos' suggested Community v3 power plan / PBO auto

Not sure how scientific they are

Single core boost 4.6 GHz

Spoiler: Single Core

Prime Blend high load test 4.225 GHZ

Spoiler: Prime Blend

Random gaming load 4.35 GHz

Spoiler: Gaming

Super Pi low load 4.6 GHz

Spoiler: Super Pi

 

[andy_mk3]

I do not use PBO. I use XFR and the 1usmus or Community_v3 powerplans succesfully since November.

The XFR menu on my board just has PBO options lol. My all-core boost is always 4040mhz no matter what I do.

 

[Panos]

The XFR menu on my board just has PBO options lol. My all-core boost is always 4040mhz no matter what I do.

PBO is always at different place than XFR. Under XRF even when the naming is "PBO" is about XFR.
Proper PBO is under overclocking

 

[Grim5]

I tried your settings and couldn't get anywhere near your results, I wonder if there is an element of silicon lottery.

that's not a surprise everyone gets different results

 

[wookiee87]

I've had to resort to manually OCing to just under 4.4Ghz all core at 1.3625v.

you sir have a bad chip, i have a 3900x clocked up to 4.4ghz all core and running 1.325v, idle load is around 31 degrees and under load is around 65-71 degrees, under custom 360mm watercooling. I'd say its the luck of the silicone lottery and in this case you may have lost.
tbh my chip stock under pbo would never go above 4.3ghz even on one core, the auto voltage was near 1.5v and all core was around 4.1ghz but temps were a bit silly hence the move to more powerful cooling.

i think most 3900x's out of the box wernt very good but that was down to poor micro code in mobo bois's, things have improved a hell of a lot since release, but as ever its key to keep updated especially your chipset drivers, as being slightly behind can hinder performance

 

[Scottx125]

Hi, so I tried your settings and they locked my CPU to 3.8Ghz. I was able to locate and enable C-states, CPPC and CPPC pref cores. But in my Bios AMD Cool'n'Quiet doesn't exist, neither does PPC Adjustment nor Power supply idle control.. I also followed your linked settings with the XFR and disabled PBO.

Edit:
Derp I forgot to turn on core enhancements >.<.

Edit 2:
Ok, so I'm still only getting 4.3Ghz single core and now 4Ghz all core on Cinebench r20 :/. Still plenty of temperature head room.

 

[andy_mk3]

I've never had any luck with PBO or XFR, any number of custom power plans etc.

Just put my 4.4 all core OC back on. 1.35V set in BIOS, vcore is about 1.308v under full load. Temps around 72C cinebench.

 

[Scottx125]

you sir have a bad chip, i have a 3900x clocked up to 4.4ghz all core and running 1.325v, idle load is around 31 degrees and under load is around 65-71 degrees, under custom 360mm watercooling. I'd say its the luck of the silicone lottery and in this case you may have lost.
tbh my chip stock under pbo would never go above 4.3ghz even on one core, the auto voltage was near 1.5v and all core was around 4.1ghz but temps were a bit silly hence the move to more powerful cooling.

i think most 3900x's out of the box wernt very good but that was down to poor micro code in mobo bois's, things have improved a hell of a lot since release, but as ever its key to keep updated especially your chipset drivers, as being slightly behind can hinder performance

I can def run it at 1.35v, but I personally want the extra stability so I run it slightly higher. I also resorted to OCing the individual CCX's, 2 of them are 4.375mhz, 1 4.4ghz and 1 4.25ghz.

 

[Scottx125]

Update. Was able to get single core speed up to 4,566.8Mhz. All core speed still sucks though. 4,046Mhz. Gonna keep tweaking around.

 

[wookiee87]

what about your chipset drivers are they fully up to date? are you running stock with pbo enabled if so just over 4ghz all core is normal, some chips can run a bit quicker but most wont

 

[Scottx125]

what about your chipset drivers are they fully up to date? are you running stock with pbo enabled if so just over 4ghz all core is normal, some chips can run a bit quicker but most wont

Perhaps, my issue is that there's still plenty of thermal headroom for a few extra Mhz.

 

[Skynet5]

Tbh I played around with loads of stuff. Paper and paper and excel files of results. The best results?

Normal with offset of around - 0.625v

4.650 boost and easy all core load of 4.175 (soak tested)


Im on a Master mobo and it's clear tinkering with anything other than above is just bad.

Temps and volts are great and I get brilliant light load single threaded performance and pretty damn good all core load clocks.

 

[wookiee87]

you'll find the more you push your thermal headroom will quickly run out, happened to me trying for 4.6ghz all core under my custom loop and temps were over 85 degrees and constant crashing, voltages pushing up near 1.455v which isn't very good for the chip, so i backed down to 4.4ghz all core with less voltage and called it a day

 

[andy_mk3]

Tbh I played around with loads of stuff. Paper and paper and excel files of results. The best results?

Normal with offset of around - 0.625v

4.650 boost and easy all core load of 4.175.


Im on a Master mobo and it's clear tinkering with anything other than above is just bad.

Temps and volts are great and I get brilliant light load single threaded performance and pretty damn good all core load clocks.

I tried those exact settings along with a bit of +/- on the offset. My best all core was about 4, 117mhz and boost was barely touching 4,500mhz single core.