Ok, it clearly would have worked without acceleration, it was a pure CUDA bug.
Please try version 1.0.9.3
Summary of 1.0.9.3beta Test Results. Please see my first post
here for complete testing parameters and results for all versions.
Test 12 Rerun 2 (1.0.9.3beta/nVidia Driver: 375.95)
Source material: Torchwood Series 1 D4 pISO
Source Drive: Hitachi 2TB 7200rpm SATA III HDD
Copy Mode: Complete copy to BD9 ISO using CUDA Decoder CUDA Encoder at Highest Quality re-encode
Result: 23.10 GB to 8.40 Gb in 12:57
Test 18 (1.0.9.3beta/nVidia Driver: 375.95)
Source material: Torchwood Series 1 D1 pISO
Source Drive: Hitachi 2TB 7200rpm SATA III HDD
Copy Mode: Complete copy to Custom (BD9) ISO using CUDA Decoder CUDA Encoder at Highest Quality re-encode
Result: 22.55 GB to 8.36 GB in 13:16
Looks like the Complete copy is working okay again.
Other 1.0.9.3beta retests:
Test 2 Rerun (1.0.9.3beta/nVidia Driver: 375.95)
Source Material: The Legend of Tarzan pISO
Copy Mode: MP4 File container using CUDA Decoder and CUDA Encoder at Highest Quality h.264 transcode
Result: 2.34 GB completed in 07:59 or 330 fps
Test 6 Rerun (1.0.9.3beta/nVidia Driver: 375.95)
Source Material: The Legend of Tarzan pISO
Copy Mode: Partial Disk/Folder/ISO to Folder using CUDA Decoder and CUDA Encoder at Highest Quality re-encode
Result: 23.16 GB completed in 08:23 or 315 fps.
Test 13 Rerun (1.0.9.3beta/nVidia Driver: 375.95)
Copy mode: MP4 File container using CUDA Decoder and CUDA Encoder at Highest Quality h.265/HEVC transcode
Result: 2.34 GB completed in 08:59 or 294 fps.
Test 19 (1.0.9.3beta/nVidia Driver: 375.95)
Source Material: The Legend of Tarzan pISO
Copy Mode: Complete copy to Custom (BD9) ISO using CUDA Decoder CUDA Encoder at Highest Quality re-encode
Result: 29.94 GB to 8.26 GB in 11:03
Only software encoding remains an issue for my setup due to low processor utilization.