Have you read about the Google TPU? It's got 65536 ALUs running in parallel turning out a result every clock:
https://www.nextplatform.com/2017/04/05/first-depth-look-goo...
They claim faster memory (GDDR5?) could easily triple the performance which should bring it to 270TOPS or so. I don't think extending AVX is going to get there any time soon.