Originally Posted by resiroof
it did not seem tp address my particular drive.
It doesn't address that *specific* drive, but it is a wealth of good solid information, and that includes usable sizes, since you will not be able to use all of your capacity. The 1.5TB drives are a higher capacity then the S3 and TivoHD can handle, in an internal situation you have to throw away the excess capacity.
Addressing every single drive that works on an S3 would not be feasible, addressing which drives do not is the approach taken. It also addresses your question on the cable to use.
That's the best thread to post your questions on regarding expansion.