I would then assume you are just as skeptical of the other 28nm projects out there as well (KnC, Cointerra, etc.)?
I think comparing a general purpose CPU and a bag of logic that does a bunch of right rotates, AND, XORs, and appends is a bit disingenuous.
http://en.wikipedia.org/wiki/SHA-2#PseudocodeThe fact that Bitfury was able to produce a 55nm that hashes must be a freakin' miracle.
I'm not really skeptical, as almost 1/3 of what TSMC ships out right now is on 28 nm. Which is, I believe, about the same quantity as on 55/65 nm at the current time. But I would be surprised if the ease and cost of developing at 28 nm were the same as for 55 nm. You should also keep in mind that Penryn was a die shrink of the Core 2 microarchitecture, so there was really not a lot new going on there (probably why the first tape-out was so dramatically successful).
What may really kill these chips in terms of development time is that they've selected pretty big die areas for them. At 324 mm^2, HashFast will have a huge problem if they don't meet thermal specs at 250 W as they'll be next to impossible to cool or will not meet specified hash rates. This was the same problem AMD hit early on with their Bulldozer processors, and the Bulldozer series of processors were slightly smaller than this. I would say that anyone who is claiming a 324 mm^2 chip with a target TDP of 250 W can be easily overclocked 25% should be considered suspicious.
hi TT, always nice to see you around!
That chart is from 2009, back in the dark ages Before Satoshi. 28nm silicon is cheap and easy now.
Inherently vastly redundant much like a GPU, the GN is much less complex (logically and physically) than modern CPUs like Bulldozer and Core2. Such redundancy vastly increases margin for error as faulty registers/hashing units are simply disabled. Sync issues are also trivial due to the perfectly parallel nature of hashing and low clock speeds.
One advanced feature confirmed for GN is on-die thermal management. While not exactly Powertune (sorry that IP isn't for sale
) the function is equivalent - chip gets hot, chip slows down until it cools off.
IDK exactly how huge/hungry my 7970s are, but they definitely run well over 125% with stock cooling and Powertune +20.
Given their sweet performance-enthusiast-sourced aftermarket liquid-cooling, HashFasts will crush.
