Here's a video I made today showing comparison of T-9 11.5 vs. S-9 12.0 variable frequency power draw at the wall. Uses more power, but runs cooler.
At 210 VAC
T-9 uses 1352 W, hashes at 11.5, highest chip temp 80C
S-9 uses 1329 W, hashes at 12.0, highest chip temp 94C
https://www.youtube.com/watch?v=yHJzo7A312c