webjapm :
I'll try with prime95 when I get home this afternoon, with 1.35v and 3900.
the reason I'm suggesting Prime95, is that it's well and good OC'ing with just numbers in mind, but the key thing is to make sure the OC is stable.
With Prime your testing the CPU at it's absolute max load to determine any instability, and also to what degree your CPU heats up. When you run Prime, use someting like HWmonitor to monitor your CPU temps. This is important. When Prime runs, the CPU will heat up quickly, but it will max out at a given temp, 80c considered to be the max for a longterm OC. My CPU runs at 3.9 1.375 @ 72c. Every CPU is different, thats why you need to check/stress all the way untill you've gotten your desired results.
Id strongly suggest stress testing at your first setting .ie 3.8 with 1.17v. You need to start at a base level and work up in increments. Testing along the way to ensure stablility. Otherwise i fyou don't stress test, you could be playing a game or something, and the PC might just crash etc. This would be because it's unstable.
The objective to get the best stable OC you can. If you want to PM for any info, I'm happy to offer help.
I would say that at 3.6-3.8 you should be near 1.325v. That why I believe at 1.17 it won't be stable. I may be wrong, but I doubt it.
Of course, all the info I'm advising is based on a BIOS OC, not something like Ryzen master or some software OC'ing app.