When messing around with my 5950x and PBO I wasn’t seeing a clock boost by much on the CPU. I then found for whatever reason my fans had been set to ‘balanced’ instead of ‘performance’. I now have noisier fans but am seeing more boosts in CPU speed at peak loading now. Worth checking in case boosting is being masked by thermal throttling due to obscure fan powerplan settings that you may not have noticed.
PBO undervolting basically provides temperature headroom allowing for higher boosts up to their 90°C limits but I don’t think it’s endless without increasing the base clock and making some other changes. If you already had very good cooling then chances are you were already boosting close to the PBO’s built in limits anyway.
At least as far as the 7950X3D is concerned, if the negative PBO value is set too high, performance will suffer, especially at medium loads, which are often used in games. Of course, I can’t generalize everything as it varies from environment to environment.
(Just my impression).
As for behavior in real applications, not bench, the default no PBO is pretty well tuned. If you have any doubts, I would recommend the default.
However, for CPU intensive benchmarks like CB23, the larger the undervoltage, the better the score. On the memory controller.
The image is like the picture, but this is not the whole pattern.
Thank you for the answer. What is the difference? In my bios, I have 2x PBO. 1x in “advanced” > “overclocking” > “PBO”. And also 1x in “Tweak” > “PBO”. Activate 1 does not activate the second. Which one do you need to activate? Both? I don’t know what the difference is between the 2 PBOs on my bios. I can activate them separately.
Tweak is a feature assigned by ASUS (motherboard vendor) on its own.
Advanced is assigned by AMD.
Example, Ryzenmaster only sees Advanced. Therefore, relying on Ryzenmaster’s automatic settings will cause problems because they are different from the settings in Tweak.
Please note that it is not yet possible to use the best of both worlds in conjunction with each other.
If you do not use Ryzenmaster and set up manually, you should only use the settings in Tweak.
On the other hand, if you rely on Ryzenmaster’s automatic settings, it is better to leave the tweak as default and not touch it.
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In my experience for Zen 4 CPUs use Ryzen Master to get the preferred (dot) and favourite (golden star) cores, then uninstall it (who uses that).
It goes like this:
Best cores -> Golden Star
Second Best cores -> Grey Star (this one doesn’t seem to appear in Zen 4, so just ignore it)
Third Best cores -> Dot
The faster/better the core the less we can decrease its voltage, it’s already low
In BIOS (Advance -> AMD Overclocking -> Precision Boost Overdrive) set PBO to advance with negative curve per core (PBO Limits to Disable = amd cpu standard limits).
Then set all to, for example, -28, except for the preferred and favourite cores.
Preferred cores can go to -26/-27 and favourite cores should go always one or more up (-25/-26).
In case the PC starts crashing/restarting randomly without warnings, just move up the favourite and preferred cores another notch up.
Or move all of them one notch up at once, in case of frustration.
The only trick here is to know which ones are the preferred and favourite cores, they must be set always at higher values (-25>-28) than the rest of the cores otherwise they will add performance degradation or/and crash randomly over load.
These CPUs don’t need to be stressed by CoreCycles or similar, they are really well binned for high load, particularly the 7950x and 7950x3D.
In fact CoreCycles never worked for all the 7000 CPUs I had. They defend themselves pretty well on high load with all cores at -30, so it never gives back a failed core.
The medium and low load are the ones that reveal that they can’t be set to all -30 (in my case the 7600x/7700x crashed Windows at -30 all)
But it works fine to tune curves on 5000 CPUs, in fact I recommend it. Got the most stable PBO curves for my old 5800x/5900x thanks to it. In no way I could guess those numbers by trial and error.
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@joeaudacious
FYI just stumbled upon a couple of threads on Reddit, claiming Asus pulled a previously released BIOS (1101), and replaced it yesterday, apparently it was causing some CPUs to fail.
Do get the new BIOS if you haven’t already - v1202 posted 4/21.
https://www.reddit.com/r/Amd/comments/12ubu7h/am5_asus_mobos_burndead_problems/
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Whoa, thanks for the heads up - doing that update right now!
I didn’t have any problems with the 1101 bios, updated to the1202 version today. Niether one has brought any noticeable performance improvement for me. Still getting 30s in VR most of the time. It is adequate, but it seemed like at one point it was giving me 40s in VR right after the new windows install, but then it fell back to the 30s again and nothing has seemed to make a lasting improvement so far.
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The conditions seem to be Bios v.1101 on an Asus x670e-Extreme motherboard using a zen 4 x3D cpu.
Best thing to do is to update it asap for any motherboard anyway.
Your score was 30252 in Timespy?
Mine is only 27738… way below average.
7950x3D/4090. I just got my system up and running today.
My initial score was 29546, only later got it to 30252, though 27738 does seem kind of low.
Did you build your machine yourself? Have you updated the bios, reset cmos, installed the newest chipset drivers?
What other components do you have, motherboard, ram, power, cooling, drives? Is your ram optimized for AMD Expo?
Mine was built for me but after re-installing windows is when I got my best performance.
Mine is working well enough for me, but I still feel like it isn’t working as hard as it should or giving me as many frames as it should.
This system was built by a local computer shop. Bios is updated but I guess it should be noted that they had a 7900x in this before the 7950x3D arrived so they could get the OS installed and GPU tested.
Bios is updated for the 7950x3D. Chipset drivers on device manager and AMD software installer shows version 1.0.0.7 for 3D optimizer. Everything shows up to date there.
MSI MPG X670E Carbon motherboard. DDR5 is set to 6000.
Just seems like that score is very low.
I think you should re-install windows, especially since they had that other processor in there. It made a difference for me doing that. Builders don’t install windows the normal way, they use other tools to do it faster.
No. It is not limited to Asus, let alone their Extreme boards, and nor is it limited to 3D chips.
This has happened on non 3D chips, non Asus boards as well.
The current consensus is that it has to do with enabling EXPO profiles:
The SOC voltage is increased when EXPO is turned on, somehow it causes a monitoring mechanism to fail and temperatures shoot up to 250+ degrees celcius on some systems then the CPU dies.
How that chain of events occurs is still being investigated.
More here:
Getting the latest BIOS ensures that a monitoring mechanism is turned on to sidestep this issue.
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Oh nice, thanks for the info!
Today I see version 1301 beta bios available for my motherboard that says it solves the voltage issue.
I thought 1202 already “solved” it… what a mess 
I think I will wait for the next non-beta version - seems like they are in a bit of chaos 
Anyway I checked my HWinfo and ram is seemingly at 1.35v for the DOCP setting I am on, so should be OK here 
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Yes that is quite something.
The previous release (1202) introduced a thermal monitoring mechanism to prevent temps from shooting up.
In the new one (1301 beta) they decided to hardcode a conservative limit on SOC Voltage (1.3v).
I don’t know if they did that out of an abundance of caution, or if they did it because the previous monitoring mechanism was not enough to prevent some CPUs from frying.
The thing is, capping SOC Voltage may limit memory overclocking on some chips, depending on the characteristics of the memory controller (Silicon Lottery).
but 1.35 is higher than 1.3 that they are limiting it to.