I was gonna jump right in on 237.5 with mine since someone said if they can't handle that then they most likely can't do anything lower which means perma stock which right now all four of mine are stable at 218.75 ~440. Seems I got lucky and got a good batch where as some have speed issues on stock an end up having to DC insread of OC their units.
Ideally I'd like to try 250 but I hear that offers mixed results, even on good machines like mine but man would I love ~500 on all four of mine. I will try i on at least one machine to see how it works instead of OC'ing them all at the same time which some people do without seeing how on machine handles it.
But most people do seem to agree that 237.5 seems to work quite well for everyone who starts out with stable stock freq machines like me doing ~440.
On my batch 1 they sucked as they only like 212
On my batch 4 they were good at 218 then 225 then 237 bumped them to 250 they crashed and now no longer like 237
so I was doing 940 at 237 .
I now do 890 at 225