SIFT to reduce tractography biases in tractogram - tcksift

Dear Experts,

I am running step 15 of the fixel pipeline and tcksift finishes creating a homogeneous mask, segments the FOD, maps tracks to image and then basically crashes my system. It still appears that tcksift is running but only at ~5% CPU. Nothing else on my computer is running and it’s virtually unusable. I am assuming this may be a memory issue. I believe that I have enough space in the /tmp directory. I believe its still running but I am wondering how long this process should take as its been ~2 hours.

Thanks in advance for the help,