How much should the -seed_random_per_voxel of the tckgen command be set to?

Hello everyone,

I’m using the tckgen command to trace white paper fibers of a depressed patient. But I have a problem, that is, how much should -seed_random_per_voxel be set to?

I’ve seen some people set it to 250000 and others to 5000. This confuses me: On the one hand, I hope to set it to 250000, so the tracking time will be very long, but will it be too small to set it to 5000?