I am a little confused because JkDefrag displays all data at the end of my partitions while the Windows defragger shows the opposite.
JkDefrag shows the begin of the partition at the bottom-left of the diskmap, and the end at the top-right. Most other defraggers show the begin at the top-left, because that's where the display begins (xy is zero at the top-left of the display). Disk optimization moves all data to the beginning of the disk, and that results in data "floating" above empty space. Bits and bytes don't care about gravity, ofcourse, but it bothered me somehow, instinctively. I tried it the other way around, I liked it better, and kept it that way.