(Core disabling OCing)Another ryzen post

[MeDownYou]

Curious if anyone has tried to disable cores in the bios and overclock a single CCX on any r7 chip basically. 

[Evanair]

Yes, but not to the full extent you're asking. I built a my computer for rending 1st, gaming 2nd. So I was testing what I was looking for, with a few requests thrown in.  Cinebench scores dropped by around 40%.  Got all the way down to 2 cores, just to see.

 

8 cores - SMT on - CB15 - 1860

8 cores - SMT off - CB15 - 1000ish (didn't record number)

 

Further tests within Cinebench are basically able to do in a linear falloff, I didn't record numbers but I did it for all down to 2 cores. 

 

As for gaming, I noticed a bit of a bump when I disabed SMT, but not enough to justify having to clear CMOS every time I wanted to reset the damn thing.  4 cores in gaming is the one thing I never tested (I got bored with clearing CMOS and having to reset everything over and over)

[SpaceGhostC2C]

You can follow the series of tests by @Evanair here:

 

You want find exactly what you look for, but still an interesting read.

 

There have been others asking the same without success:

 

And then there was a report from a test disabling 4 cores, but not really pushing the OC. Instead, they clocked the 4 remaining cores (not sure if the same CCX or not) to 4.0GHz, they downclocked a 7700K to 4.0GHz, and then compared results between them, to learn I don't know exactly what