Old thread I know,
but you can't underclock an S9, so drop that idea right now.
You can with the 14Th/s Batch 1 (running the old firmware) - I have it down to 11Th/s (stable) @500MHz with only 45% fan speed.
The latest firmware allows you to set a freq on initial firmware install. So I guess you COULD downgrade with a firmware install
Thanks for the advice - I know it's been a while since I posted in this thread but things got worked out - I have 3x S9's hashing under my college dorm bed (extra fan intake in; exhaust vent out; amazing space-age material to create tents for heat/noise isolation). Pretty cool setup.
I can confirm that the EVGA-1600 Platinum's work great nonstop with S9's, any model. If you're buying a $2k machine it doesn't rly make sense to skimp $100 on a cheaper PSU...
The new EVGA-1000 G3 is amazing on my R4's. I'm considering hashing another R4 but it'd have to be split circuit - that is, like a 550W PSU powering each board from 2 separate circuits (I can have one powering the controller as well). I know this works on the S9 and S7 - does it work on the R4?