"torch.cuda.OutOfMemoryError: CUDA out of memory. Tried to allocate 6.39 GiB. " BUT I have 64gb graphic card installed

[Ashtavakra7]

Hello,
thanks for the nice library. I am new to the cuda pytorch. When I change orders > 20 any of your example simulations I get this following error with cuda out of memory but I have 64 gb graphic card but unable to allocate 6.3 gb??
File "/home/benchmark.py", line 81, in
sim.set_incident_angle(inc_ang=pol_ang, azi_ang=azi_ang) # set incident angle
File "/home/rcwa.py", line 174, in set_incident_angle
self._kvectors()
File "/home/rcwa.py", line 1504, in _kvectors
Vtmp1 = torch.linalg.inv(self.Vf + self.Vi)
torch.cuda.OutOfMemoryError: CUDA out of memory. Tried to allocate 6.39 GiB. GP

thanks for the help