I recently decided to replace the bulk of the HDDs in my desktop with an Hitachi 7200 2TB. I have installed my OS and applications onto my Vertex 2 120 and then installed all my documents, pictures, movies and all of my Steam games (40ish) onto the 2TB. Everything seemed to be fine until I tried my first defrag. I started a defrag on just the 2TB around 12am last night with Piriform Defraggler. It's now 6:47PM the following day and I'm up to 78% completion. What gives? I've never had an issue before and almost swear by Piriform's product line like CCleaner. The only change is the drive size. Is there a defragging program optimized to work with a 2TB HDD? I have a license code for Auslogistics Boost Speed as well but don't want it installed unless I have an actual use for it (messed up an older config because I didn't take the time to learn what everything did.. It did some boosting alright!. If I can not screw with the registry by installing several programs, that would be ideal.
HDD: Hitachi 7200rpm 2TB HDS723020BLA642
Size on Computer: 1.8TB
Just saw your post and wanted to tell my experience. I recently got myself a 1TB drive basically for photo work. A friend told me to go in for one of the commercial utilities as he apparently faced issues similar issues while defragmenting with a freeware. I personally have not tried Defraggler, but I am a regular CCleaner user. I am pretty happy with my auto defrag program which runs in the background and seems to be defragging without any issues. You could perhaps try any of the trial versions and see if there is a difference in the time taken.
You can get more info on each product by clicking the product's image and it will give details on the product's features and why it placed where it did.
The top-placing ones are pretty good, and I know for a fact that the "Pro Premier" version of the gold medal winner has a "Terabyte Volume Engine", which is a defrag engine that is designed to deal with large disks -- that's probably what you need.