[nsthorat]

Or you improve your algorithms and use the existing hardware (think distributed computing on cheap HDDs).

[jorgemf]

Companies will improve the algorithms and go low level with hardware instructions. The problem with GPUs is that they have special instructions for some operations. Not using them can be 20 times slower. You are not going to improve the algorithms 20 times, ND if you do you can still improve it another 20 times with hardware instructions. You do both if you can. That is a big saving in electricity in data centers.