That's not what's at issue. FLOPS is not, in fact, FLoating Point Operations Per Second but the numeric result of running a very specific, standardized benchmark from the LINPACK codes solving a large, dense system of linear equations. It is a benchmark that is meaningful for most scientific and technical disciplines, but says *nothing* about the ability to crank out SHA-256 hashes.
FLOPS
is floating point operations per second. LINPACK FLOPS are just meaningful in the context of the TOP500 supercomputer rank because this organization decided to use this benchmark to establish the rank. A supercomputer might achieve "
x" FLOPS on linear equations with LINPACK, "
y" FLOPS when doing protein folding, and "
z" FLOPS when doing some other work. The "x" FLOPS value of the LINPACK benchmark is no more significant than "y" or "z".
All are a fraction of "t", the theoretical peak FLOPS of the hardware (which can often be reached within 1-2% with a useless loop of multiply-add instructions). This theoretical peak
can be used to predict the performance of SHA256-based Bitcoin mining because it scales linearly with the peak theoretical integer performance of a chip, which is itself directly related to its peak theoretical FLOPS performance by a fixed ratio. For example, there is exactly a 1:4 ratio between the number of integer and double precision floating point instructions that an HD 69xx series GPU can execute.