Both the 1tb Western digital caviar blue and Western digital caviar black are 7200rpm drives and both have 64mb cache so why is the caviar balck 20$ more, i have heard that the caviar blacks are gaming drives and blues are just normal drives and the blacks have higher quality parts and run 10% to 15% faster
blacks are higher quality, but the blues aren't bad either. the biggest diff is that blacks come with a 5 yr warranty, and the blues 2 or 3 yr, don't remember offhand. and blacks also have limited time error correction, which is really only applicable in RAID. and the blue only has 32mb of cache... if your writing large amounts of data all at once, such as with fraps, get the black, itherwise, the blue will be just fine.
I can't speak from personal experience, but I have done alot of looking around at hard drives, and you can't go wrong with WD.
IMO Blacks are the best for everything, the only other drives i would ever use are the WD Green for a server build because they are cheaper
that's waht reds are for