Can confirm 1 works for me. I also tried 4, with that one after selecting 37 the max gets raised to 39, but any oc settings over 37 don't stick, so you're stuck on 37.
The problem with 1 is that is seems a bit buggy with the voltage regulation. Fixed voltage works, but is kinda useless. Dynamic seems iffy, I have to target 50~100 mV over the static setting in order for it to be stable. The settings I used for x37 with MC v7 are definitely not stable with MC v1. Frequency regulation seemed wonky too, specially at idle.
Long story short, I can get 4.1GHz on a single core. Anything more thermal throttles like crazy. Any less voltage -> reboot. My CPU does not seem very good; it can do 3.7 @ 1.08, 4.1 @ ~1.20, and then I tried 1.35 V and it ran for a few seconds at 4.5 but ended up rebooting (I suspect something strange is going on, because with newer frimwares the lack of voltage usually results on a bluescreen or lockup, not reboot.)
So yeah, maybe with better cooling. Does that liquid thermal paste really help? I go from 50 to 90º in less than a second and back again too, I don't know if that's a sign of bad thermal conductivity or not (I'd say it is). Last time I repasted I didn't notice any improvements.