That line of reasoning would take the shape of a &quot;no true scotsman&quot;.<p>As long as we&#x27;re talking about alternative hardware architectures that can enable computation speeds otherwise not possible, we ought to include parallel computers, GPUs, FPGAs in the mix. The connection machine doesn&#x27;t count?<p>Why exclude FPGAs? As long as I can have a program that will reprogram an auxiliary FPGA to do what I want more efficiently, it counts as an alternative processor with a potentially odd architecture where a gate acts as a switch in one program and works as a memory bit in another. They are named &quot;programmable&quot; for a reason.