[gmx-users] gpu usage

[p buscemi]

Dear Users,
I am getting reasonable performance from two rtx -2080ti's - AMD 32 core and on another node two gtx-1080 ti's -AMD 16 core i.e 20-30 ns/day with 300000 atoms. But in all my runs the % usage of the gpu's is typcially 40% to 60 % . Given that it is specialized software, I notice that Schrodinger will run a single gpu at 98%.. So the cards are apparently not defective
The cpu runs at 2.9 Ghz. and the power supply a 1500 watts
A typical run command might be" gmx mdrun -deffnm sys.npt -nb gpu -pme gpu -ntmpi 8 -ntomp 8 -npme 1
I have gone over http://manual.gromacs.org/documentation/current/user-guide/mdrun-performance.html (https://link.getmailspring.com/link/1566319015.local-8bb7ace6-bf71-v1.5.3-420ce003@getmailspring.com/0?redirect=http%3A%2F%2Fmanual.gromacs.org%2Fdocumentation%2Fcurrent%2Fuser-guide%2Fmdrun-performance.html&recipient=Z214LXVzZXJzQGdyb21hY3Mub3Jn) ,and tried to incorporate what I could.

The installation was basically that given in the manual for build 2019.1:
cmake .. -DGMX_BUILD_OWN_FFTW=ON -DREGRESSIONTEST_DOWNLOAD=ON -DGMX_GPU=on -DCMAKE_CXX_COMPILER=/usr/bin/g++-6 -DCMAKE_C_COMPILER=/usr/bin/gcc-6
Both 2019.1 and 2019.3 run well but with the same "reduced" % workload.
I am curious to learn why the gpu's are not pushed a littler harder. Or is this a typical result ? Or are there improvments to make in my setup.
Paul