I was getting very poor performance on my iMac for some time but never gave it all that much thought. Recently though it was getting smoked by my MBA. I did some searching and found that the problem was related to my Bootcamp partition. I guess Spotlight tries to index bootcamp but because of the NTFS drive it causes a bottleneck. I use WinXP but I read about other people having issues with Vista and 7. Here is what I did: 1) Create a blank Notepad txt document at the root level of your c: drive called .metadata_never_index.txt 2) Run CMD 3) ren c:\.metadata_never_index.txt .metadata_never_index 4) Restart Windows 5) Restart Mac OS The idea is to create a file at the root level called .metadata_never_index You need to use the rename function in CMD to remove the .txt. Having this file on your c: drive will tell Spotlight to ignore Bootcamp. This drastically has sped up the performance of my Mac OS. Many applications would take between 4-20 bounces of the App before they opened. Now most open on the first and the worst offender (Chrome) is usually 3-4. Switching between Spaces is much quicker also. Startup on Windows is faster as well. Hope this helps other people. I don't know if everybody is having this problem or just certain people. I think my problem may have started when I upgraded from Leopard to Snow Leopard so if you do or don't notice improvements with this fix be sure to mention what your original and current OS versions are.