Since JPEG is so compute-intensive, many people suggest that using an
FPU chip (a math coprocessor) should speed it up.  This is not so.
Most production-quality JPEG programs use only integer arithmetic and so
they are unaffected by the presence or absence of floating-point hardware.

It is possible to save a few math operations by doing the DCT step in
floating point.  On most PC-class machines, FP operations are enough slower
than integer operations that the overall speed is still much worse with FP.
Some high-priced workstations and supercomputers have fast enough FP
hardware to make an FP DCT method be a win.

DSP (digital signal processing) chips are ideally suited for fast repetitive
integer arithmetic, so programming a DSP to do JPEG can yield significant
speedups.  DSPs are available as add-ons for some PCs and workstations;
if you have such hardware, look for a JPEG program that can exploit it.