A couple of questions:
1. Are your ASIC estimates scaled up estimates based on real measurements of smaller prototypes or is it purely theoretical at this point?
2. How did you get to the Altera FPGA estimates?
3. I could imagine you develop on FPGA's first to put the design into (digital) ASIC later or something, is this how your engineers went about?
4. Why Altera FPGA's as a comparison and not one of the many other brands? Have you considered significant differences (advantage/disadvantage) of implementing on other FPGA brands?
5. Since in this business time-to-market is very important, why don't you go for FPGA implementations at first? Isn't the development time for FPGA based designs much shorter?
PS: if this is not the first time one of my questions pops up I apologize in advance. I haven't read all of the thread yet...
1. Are your ASIC estimates scaled up estimates based on real measurements of smaller prototypes or is it purely theoretical at this point?
They are scaled up estimates based upon the Stratix V pictured in the OP.
2. How did you get to the Altera FPGA estimates?
Timing analysis. We also benchmarked out miner against the open source miner kramble supplied and came to the conclusion that it is faster and requires less silicone area. This is mainly because we share some operations between cores. Krambles work is in another section of this forum, it is tested, proven and well documented. I would recommend using it to other companies too.
3. I could imagine you develop on FPGA's first to put the design into (digital) ASIC later or something, is this how your engineers went about?
FPGA mining could not go below 1.5$ per khs, we completed our FPGA miner, if you do not buy en masse then that figure goes to 4$ / khs. I do not think anyone would buy that.
We considered using Artix 7, but it only supports DDR3 400MHz, this made it unusable.
4. Why Altera FPGA's as a comparison and not one of the many other brands? Have you considered significant differences (advantage/disadvantage) of implementing on other FPGA brands?
There is no difference between Artix 7 and Cyclone V FPGAs for cheap FPGA miners and Virtex 7 and Stratix V FPGAs for ASIC prototyping. And we have one of Altera's field application engineers on our team, so device choice was straightforward.
5. Since in this business time-to-market is very important, why don't you go for FPGA implementations at first? Isn't the development time for FPGA based designs much shorter?
Yes, and we have them done already. But the $/khs is not practical. Unless you are using aftermarket FPGAs or own the facilities, there is little point in producing hundreds or thousands of FPGAs no one will buy.