Not sure why this is happening but nearly all of the heavily fragmented files on my hard drive are tixati downloads. most of these files are at most 1-2 gig in size but are reporting thousands of individual fragments per file. I am wondering why tixati downloads are fragmenting so much? This is on a 2TB drive with over 500 gigs of free space so it really seems odd that tixati is not allocating contiguous space for it's downloads or at the very least attempting to optimize the files after the download completes

go to Settings->Files

if you set the 'File allocation' to 'Full Pre-Write' that should keep down on the fragmentation.