As for the "best yields in the world", I think that everyone knows that was Sanders hype. That quote is also 2 years old at least.
I prefer to call a lie a lie. Sanders said that no more then 6 months ago.
I claim ignorance because I do not know how much of the Fab's capacity must be dedicated to both Hammer and Barton even though they are not in production. With the long lead times from raw wafers to final product, I would expect that some fraction of the tooling, instruments, floor space, or what have you must be dedicated to those lines. I do not know what that fraction is. You say it is insignificant. Can you provide a reasonable estimate and some reasonable basis for that estimate?
I don't know how much floor space, if any, would need to be reserved exclusively for SOI as separate from the standard process, but for engineering experiments I wouldn't expect the wafer count to be more than a few 10s of wafers to check out a new stepping and maybe a few thousand units for reliability experiments. Those experiments probably wouldn't need to be repeated for additional metal only stepping changes. With Barton on the standard non SOI process it would use the same flow as TB.
The excuse that AMD needs major portions of their Fab capacity for new product/process development was worn out nearly a year ago when AMD zealots were trying to explain away the inexplicably low Fab output when AMD couldn't meet demand. They claimed it was used for .13u material that was in line in Q4. Unfortunately it was 6 months before any of that hypothetical material made it's way out the door in a slow trickle and shot down that attempt to explain away apparent yield problems. Today we are seeing the same excuses resurrected again using smoke and mirrors to come up with an analysis of AMD's fab utilization that doesn't expose a yield crash, at least for SOI.
If TB has decent yields then half the fab is unused. If AMD has half a fab available then why are there no Hammers unless the SOI process has major problems, which AMD has denied, or Hammer has major problems which AMD has also denied. The point being that not all of AMD's statements can be true at the same time. When a company knowingly makes false statements I call it lying, you may use whatever term you choose.
EP
