too bad, I think my miners won't hit 453GH/s at 225MHz...
They should, but if they can't, take it up with Bitmain.
Only worthwhile if you're lacking by 5%, it would seem...
I have not had good experience with their support/RMA folks. It took me a month to get a single S3 hashing board replaced, and that's when I had it fail, put a deposit so they could ship it before they received my return, AND they didn't send me the blade with heatsinks.