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.
Similar experience here. S3 clocked down to 212 as it would not stabilise at stock. Finally decided last night to have a fiddle as I had a bit of time on my hands. After removing the cover I did the following -
Straightened out the heatsink fins as some were bent close to where the screws were.
Tightened up one screw which was loose on one heatsink.
Pushed the cables to make sure they were seated properly, they all looked ok, no "give" when pushing.
Put the cover back on and instead of putting the cables into the sockets closest to the ethernet port I decided to try the other two.
Hooked it back up, checked the results after a couple of hours and it was hashing at 420. Decided to put the clock back to stock and it's been hashing at 440 for the last 24 hours!
Really strange as the only thing I felt I really did was swap the cables. Maybe it just needed a bit of TLC and me stroking its internals made it happy!
OK so I'm back to square one with this! Went back to fluctuating between 380-410 after about 72 hours on stock setting. Reset it back to 212.5 and it's hashing steadily at 410 now.
Just had a thought, has anyone ran one without the cover on? I'm thinking I might try it this weekend, wondering if the controller is getting too warm as its directly above the inside heatsinks and not to the side as with the S1. I understand the cover is required for decent airflow across the outside heat sinks so I'll either make some sides or blow air from another couple of fans on them.