SO then should we understand or assume that this is what BFL did and they use 2 Hardcopy chips from Altera or did they do something else ?
I though we were getting custom BTC ASICs like in a couple of years not right now. Maybe Altera is not a real ASIC and just one that is generic but was customised for mining ?
Assuming this is real we won't know for sure until someone buys one and removes the heatsinks.
Still the theory isn't that these aren't custom ASICS but instead are structured ASICS (sASICS).
A structured ASIC is partially "pre-built" with a large number of LUTs. Very similar to an FPGA. However in a FPGA all the routing of every possible combnation between LUTs are part of the chip. This adds a lot of overhead. In a sASIC there is no routing in the chip. It is "incomplete".
The only part that is customized in a sASIC is the routing. A mask is built for the routing traces and a routing layer etched. This layer is then sandwhiched w/ the "pre-built" logic layers. Essentially is a step between a custom ASIC and an FPGA. Since only one layer is customized it has a cheaper upfront cost than a custom ASIC (hundreds of thousands vs millions of dollars) and since it has no pre-built routing (for every possible combinatio between LUTs) it has a lower per-unit cost than an FPGA, and higher performance.
So
Custom ASIC - highest upfront cost, lowest cost per chip, higher performance per chip.
Structured ASIC - medium upfront cost, medium cost per chip, medium performance per chip.
FPGA - no/low upfront cost, highest cost per chip, lowest performance per chip.
