So I'm a newb when it comes to overclocking... I'm in canada so we have 120v outlets, what's the safest max I should overclock to? (Could, maybe not should)..
You shouldn't, the stock PSU can't even handle running stock. You should also consider installing a 240V outlet if you have a few miners.
This information is incorrect. I have been able to overclock to 212.5 100% of the time with no issues whatsover on stock PSU running on 110V. Yielding about a 5.5% increase in hashrate. A majority of the units I have experience with, will overclock at 225M with no problems. Just make sure your ambient temp is cool enough to keep the S4 at sub 65C temps. If you can't keep temps cool enough you will start loosing chips and they'll show up with X or completely missing from the status.
And I've had more than 1 PSU fail running at 200MHz. Hard to say who's right. At 225MHz and stock voltage, the entire miner (4 hash boards + controller + fans) draws exactly 120A DC from the PSU, and the PSU is rated for 120A. If it were a quality unit, there wouldn't be any problem running 225MHz on it, but it isn't.
I'm convinced that all of the S4 PSUs will have died within 6 months max. If you're going to overclock with it, make sure you have a backup ready or you'll be pissed when your S4 is a temporary paperweight and you lose all the ground you made by running overclocked. Better yet, replace it now and have peace of mind.
Replacement PSU's are pretty expensive... I thought the newer batches had better PSU's? Am I incorrect?
The trick is using cheap (but much better quality than ATX) server PSUs. I picked up 2x 2880w server PSUs for 90$ the other day.
The batch 2 and newer PSUs were improved vs batch 1, but they're still terrible. If your PSU has a sticker on the side of it, it's the newer model. I've had failures with B1 and B2+ PSUs.
