I have the same problem with my 7900x (delided by caseking)
OCUK are part of Caseking i believe which is where i got mine. I'm curious if core #5 is your preferred core in bios for turbo boost? I noticed that under full load my highest core temp is always core #10 which is the highest preferred core in bios and the one which turbo boost prefers to use along with core #3 as the second preferred core although that temp is much better.
I've overclocked with offset mode for each core up to 4.5GHz
In my case in BIOS core #1 and #7 are marked with *
My other OC settings:
CPU input voltage - 1.850
CPU Load-line Calibration - Level 7
CPU Current Capability - 200%
AVX/AVX-512 - 3
energy savings - off
memory working XMP 3200MHz for F4-3200C16Q-32GVK
I think that's all changes that I've made.
My knowledge about OC is very basic so maybe my settings are just simply bad.
On stock settings, core #5 also have bigger temperatures around 12 degrees but with OC'd that difference is HUGE almost 20 degrees. I dont think it's normal.
Can't tell what is the source of this problem.
Don't have any problems with stability on my system, not a single BSOD, rebooting around every 2 weeks or forced by windows updates.
I really would like to push my CPU little higher but I'm afraid because of this stupid #5 core.
Temps on screenshot after around 15 minutes of using no_avx prime95 and Kraken X62 (tried preapplied NZXT compound and right now using Kryonaut)