My lowly two B4 S3s are each powered by a Corsair CX500 (non-modular version with only two PCIe power connectors).  The CX500 accommodated the S3's 250M clock without any noticeable issues whatsoever which drew 425W at the wall at 29C ambient room temperature.  That's just under 80% load on the CX500.

The following are some data that I was able to jot down while in the process of exploring the S3/CX500 combo (hopefully the dude who's attempting to compile such data can use it).  Note that these figures are averages between my lowly two S3s (except for the ambient room temperature):

Legend:  Tambient/Tdevice/Wattage/Hash Rate

@ 218.75M (stock)
35C/45C/365W/440GHs

@ 225M
35C/45C/378W/453GHs

@ 237.5M
32C/43/400W/478GHs

@ 250M
29C/43C/425W/485GHs

I've set up my lowly two S3s in a V-Air (Vertical Airflow) configuration in an attempt to improve air-cooling efficiency (hot air rises).  Here are some pictures:

Pushing in cool air at the bottom and pulling out hot air at the top.


Since the less restrictive, widely-spaced chrome wire shelving now functions as a fan grill,
both intake and exhaust stock fan grills which are quite restrictive were removed for an improved airflow.

I made that suggestion since he said he needed power for 20 miners. You don't need that for 2 miners. I would suggest 12v single rail(35amp per miner) with 4 pcie 6pin connectors(one wire per connector from psu). I use Corsair850tx myself for 2 miners, same as I used for my s1's. They are pricey, but they last. Most people are getting the Evga 1600 to run 3  s3's with also. And YES minersource.net is legit(ran by bobsag3)

Note: a cheap psu to run two "not overclocked" s3's

http://minersource.net/products/dell-750w-psu-slash-adapter


https://www.amazon.com/dp/B008RJZQSW/ref=cm_sw_r_udp_awd_fJZ4tb162J9HG

I'm pretty aware how just how shitty it is, but unfortunately after re-pasting two units I saw a decrease in running temperatures but was still experiencing a steep drop off in hash after about 25-35 minutes. One of the units will spike back up to about 470 but never enough to average out to 440 without cgminer restarts.

I wish I could attribute this to poor labor skill on my part, but I'm just about 100% certain I don't suck at apply thermal paste. =/

Thanks for the help.

Do your homework.

No its for stock. For overclocked put 390 instead of 340.

Paper Clip is safe if you do it correctly and protect it from any loose or shot by sticking some tape over it.

yeah did that the paper clip route..on my KNC Jupiter 550gh from last oct 18th 2013...heck I'll probably just get the above I usually spend
more then $1.75 for other 'toys' I get a 'thrill' from in the mail....but getting a KNC Titan probably will 'also' reguire a paper clip...time to
probably step it up and dish out the 'gasp' $1.75 each for more then a couple ...I mean I may even be a big shot and get THREE!.....

(FML ..sheesh..waiting on interesting mail!)

thanks

Searing

Retail available from http://minersource.net/products/bitmain-24pin-psu-jumper-pre-order
$4.99 + Free Shipping.

Just saw this thanks for the info still cheap enough I should 'probably' get a couple.....now just to 'man up'
and get an antminer toy ..everyone else seems to have one!

Searing