what about the consumption of this setup? it's probably very high , above 590w, if your ratio is the same as before, i see no reason to overclock
but if you are getting something better like 1554 at 700-800, it would be a good move to overclock the S5
this OC should work with every 28nm board and not so much with the future 16nm or 14nm
Do you know! i' am not using PSU 700W or 800W, but i am using
PSU GIGABYTE 500W of each Board
BECAUSE I FOUND 750w PSU COST ABOUT 266 USD EACH, SO I BOUGHT 2 OF GIGABYTE 500W CUST 75 USD

Bitmain generally recommends to use only 1 PSU to power up your miner. Using 2 PSU to power the same miner can cause issues like voltage variations that can be harmful for your miner.
You could use a more powerful PSU to power two miners.
At least, thats what bitmain says. Also, try to use good PCI-E cables. On my local bitcoin miners Facebook page, people use better components to build their own cable.