  We introduce a new GPU-accelerated general-relativistic magneto-hydrodynamic
(GR-MHD) code based on HARM which we call cuHARM. The code is written in CUDA-C
and uses OpenMP to parallelize multi-GPU setups. Our code allows us to run high
resolution simulations of accretion disks and the formation and structure of
jets without the need of multi-node supercomputer infrastructure. A $256^3$
simulation is well within the reach of an Nvidia DGX-V100 server, with the
computation being a factor about 10 times faster if only the CPU was used. We
use this code to examine several disk structures all in the SANE state. We find
that: (i) increasing the magnetic field, while in the SANE state does not
affect the mass accretion rate; (ii) Simultaneous increase of the disk size and
the magnetic field, while keeping the ratio of energies fixed, lead to the
destruction of the jet once the magnetic flux through the horizon decrease
below a certain limit. This demonstrates that the existence of the jet is not a
linear function of the initial magnetic field strength; (iii) the structure of
the jet is a weak function of the adiabatic index of the gas, with relativistic
gas tend to have a wider jet.
