Hello,
It seems that torch is taking use of all the GPU and consuming less memory, which is good I guess. I think your code in tf is not well optimized, the main reason behind this is that you waste time transferring data from RAM to GPU in your tf implementation.
The heat level you have is not a problem I guess, normally you want to use fully your GPU so that you can ran faster. So the fact that GPU-UTIL is 99% is a good sign in fact.