@ajlueke - This writeup was very helpful!
I'm suspecting that you have a much more aggressive cooling solution than my lame ol' Noctuta NH-D15 for my 3900X CPU.
I peaked out at 65 DegC on Cinebench R23 at the "default-ish" PBO settings you suggested, and my multi-core Vcore hangs around 1.28V.
Just setting my PPT/TDC/EDC at 150W/100A/120A pushed my 3900X temperature up to 74 DegC and Vcore to 1.32 V.
It looks like my MSI X570 Ace motherboard doesn't have the gobs of headroom that you have, or I need to move to water cooling.
Probably a combination of things. Matisse in particular didn't have loads of headroom, so the issue is most likely the Ryzen 3900X you are using. I had very similar results with my 3900X as well. It seems the Vermeer processors are a little bit better in that regard.
I do have an EKWB custom loop, but at a certain point the processor is limited by the heat transfer from the IHS to the cold plate. No amount of increased dissipation will help, and the only way to get additional headroom would be to cool the coldplate below ambient.
You can try curve optimizer to get a bit of headroom on the voltage. I would look in Ryzen master and take note of the two best cores on CCD0. The numbering might be a bit different in Ryzen master vs UEFI, so keep that in mind. Next, enter curve optimizer under "AMD Overclocking" Give your two best cores a -5 voltage offset, and everything else on CCD0 a -10. Set everything on CCD1 to -20, these cores should only be used in multithreaded workloads and should never need to clock up that high.
Repeat your benchmark and see if you gained anything from a voltage headroom perspective.
Thanks for the update, that's helpful. I'll give it a shot. Can I look at the cores Win10 seems to frequently use to determine the optimal cores I should set in UEFI?
I have been trying to get my hands on a 5950X for months now, and the closest I've come is getting it into my Best Buy shopping cart before I can successfully check out.
Me and the rest of humanity. 😀
Ryzen master should have the cores labeled up for you. But Windows should be loading those cores as well, so I suppose the task manager would work.
I was able to snag a 5950X at my local Microcenter a while back. Online orders just seem to be the domain of bots these days. The Ryzen 9 5900X was actually out of stock faster at my store vs the 5950X. The 5600X and 5800X have been in stock for over a month now.