hi freesufer folks, has your new version 6 run a successful cuda7.5 gpu on ubuntu 16.04? i'm getting a core dump. jeff
here is the cmd:

recon-all -all -use-gpu -s ${filenames_arr[$i]}_freesurf -i ${sesnum_arr[$i]}/anat/${filenames_arr[$i]}.nii

first output gave:

Testing for CUDA device:
/home/toddr/Software/freesurfer/bin/mri_em_register_cuda: error while loading shared libraries: libcudart.so.5.0: cannot open shared object file: No such file or directory
Linux redshirt 4.4.0-59-generic #80-Ubuntu SMP Fri Jan 6 17:47:47 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux

thinking its a missing link i did:
sudo ln -s /usr/lib/x86_64-linux-gnu/libcudart.so.7.5.18 /usr/lib/x86_64-linux-gnu/libcudart.so.5.0

and then got:

Testing for CUDA device:
nvcc: NVIDIA (R) Cuda compiler driver
Copyright (c) 2005-2012 NVIDIA Corporation
Built on Fri_Sep_21_17:28:58_PDT_2012
Cuda compilation tools, release 5.0, V0.2.1221

Driver : 8.0
Runtime : 7.50

Acquiring CUDA device
Using default device
CUDA device: GeForce GTX TITAN Black
Segmentation fault (core dumped) 
Linux redshirt 4.4.0-59-generic #80-Ubuntu SMP Fri Jan 6 17:47:47 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux

recon-all -s sub-bbc101_ses-1_mpr_3_freesurf exited with ERRORS at Tue Jan 24 13:21:33 PST 2017

For more details, see the log file 
To report a problem, see http://surfer.nmr.mgh.harvard.edu/fswiki/BugReporting