The first rack are S1's, the second rack are S3's.
As of last night, the 12 S1's are hashing @ 2,265 GH/s, and the 12 S3's are Hashing @ 5,228 HG/s for a total of 7,494 GH/s.
After that measurement, I overclocked the S3's to 237.5MHz and am monitoring them to see which ones are capable of this increase.
This morning it seems I have 2 "problem children" that don't like the increased clock rate.
But am hashing around 7.9 TH/s.