Freesurfers,
I'd like to add my two about a recent experiment I ran with recon-all -use-gpu. (I'm using v5.1)
I took 6 T1 scans, imported them into two subjects a piece (gpu_SUBJID, cpu_SUBJID) and ran 'recon-all -all -use-gpu' on the gpu_ subject and the normal 'recon-all -all' on the cpu subjects. All gpu subjects ran on a single GTX 480.
On average, I saw about a 16% speedup using GPU hardware, which translates to about 4 hours on the hardware I'm using.
Qualitatively, the final inflated surfaces and {w,g}m boundaries are very similar.
Two questions:
1) Would you recommend -use-gpu for "production" analyses using FS v5.1?
2) Separately from the above experiment, I ran one gpu subject using 4 GTX 480s and saw no significant time difference. Is this to be expected, ie your CUDA code doesn't scale across multiple GPUs? Just curious, certainly not a deal-breaker if it doesn't.
Thanks for your input.
Scott Burns Neuroimaging Analyst Education and Brain Science Lab Kennedy Center Vanderbilt University