Comment 4 for bug 1547599

ok, i purged all nvidia related packages and installed your request. the packages now are

libcuda1-340 340.96-0ubuntu2
nvidia-340 340.96-0ubuntu2
nvidia-opencl-icd-340 340.96-0ubuntu2
nvidia-prime 0.8.2
nvidia-settings 361.28-0ubuntu1

unfortunately, the x11 still does not start. the Xorg.0.log is the same as above but the journalctl --dmesg is slightly different:

kernel: NVRM: failed to copy vbios to system memory.
kernel: NVRM: RmInitAdapter failed! (0x30:0xffffffff:747)
kernel: NVRM: rm_init_adapter failed for device bearing minor number 0
kernel: NVRM: nvidia_frontend_open: minor 0, module->open() failed, error -5

i hope this helps. it was really nice to revive these old macs with ubuntu...