I like to tell another thing, my 2 PCI-E Power cables to S3 were a little hot.
My S3 hashrate was not stable at the rated 441Ghs but was averaging at 420. I ordered thermal paste.
Before thermal plates were arriving, I tried to plug two additional PCI-E power cables to S3.
The Antminer S3 is running at stock clocks 218.75 and PCI-E power cables are cool now.
The main reason for this post is to report that the miners stabilised at 441. Earlier it was 420.
Two thing I'm pointing out,
1. The miners plugged in continuously for 4 or 5 days and seems like it was running-in and stabilised at-last at 441.
2. Plugging the all four connectors even if you are not overclocking will some way help you.