looking to increase my tjmax setting for the cpu im running 5.3ghz all core 0 avx but my temps under cinebench after a few days uptime can go around 90c with spikes of 95 its getting close to the tjmax which would cause a quick shutdown i just want to raise it to like 110c or 115c like on my msi board i would just max it to 115c

is this setting available in the z390 dark

If there is, it would likely be in the CPU Configuration menu like an X299..I don't see a BIOS update that would add it either.

I'd be more concerned about getting the temps down rather than increasing the TjMax though..Just me.
 
Maybe the Vcore is unnecessarily high under load/the Vdroop is not enough.
 
Design guide for EVGA Z390 DARK motherboard

In the v0.00 UEFI, under OverClocking Performance Menu>Processor there is TJMax Offset.
 

 
I added 10 to the setting, and as you can see, it raised the TjMax to 115°.