Sorry to post another question so soon. I have been trying to use probtrackx2 to run seeds_to_targets on a relatively large number of targets (~80). When I do this, it takes up a large amount of RAM (44.85 GB) and takes around 4 hours. I get similar performance when using surface based seeds/targets. When I run the same command with probtrackx it uses up 1.41 GB and takes a bit less than 2.5 hours. Is this difference in performance between the two versions to be expected?