Looks like a longer tube. How did they get the efficiency up?
Downclock and downvolt each chip.
Nope. Its a new parallel powering layout which is simply more efficient. If I get a Prisma you'll be able to see it in the pictures.
That may be true but it's also underclocked. The tubes were 8.3gh/s per chip and Prisma is 7.3gh/s.
Where did you hear about this "parallel powering layout"?