Here’s a tip for those of you running World of Warcraft in Windows (sorry Mac folks), which may improve your gameplay performance.
Every time you install an expansion or patch (and as patches are released approximately monthly this can be quite often), the updater patches data into the existing data files on your hard disk. Over time, especially on hard disks which are almost full, this can lead to data fragmentation, where the data in each file is located in positions right across your disk, rather than altogether in one big contiguous lump. This means that it will take the drive head longer to read the file’s content and may ultimately slow down the game, especially in situations where large amounts of data has to be loaded, such as walking around Dalaran.
Thankfully, you can defragment the data files to make them contiguous again, which should reduce access times and allow data to be loaded more quickly. You can use Windows’ built-in defrag tool, but this will attempt to defragment your entire hard drive, which can take a very long time, especially if you have several hundred gigabytes of data.
Instead, you can use a tool such as Power Defragmenter, which can be pointed at a single file or folder. That way, you can tell it to only defragment your World of Warcraft data files and not everything else. The program is actually a front-end for a command line tool called contig, developed by Mark Russinovich who now works at Microsoft. Power Defragmenter does not include contig but will offer to download it for you when you run it. Once contig is installed, point it at your World of Warcraft data folder – usually C:\Program Files\World of Warcraft\data and let it run for a while – depending on your situation the files may be in many fragments (over 100 for just one file in my case). It’s important that you don’t interrupt the process as otherwise you may render the files corrupted, in which case you may have to re-install the game.
Note that for optimum performance you will probably need to do this after every major content patch. The next big patch – 3.1, which introduces the Ulduar raid dungeon and the Argent Tournament, as well as Arena Season 6 – is due out either this week or next, so you may want to wait until then.