Originally Posted by TbbZz
Ah, thanks for reminding me of my second question:
How much of a difference is there between a 5,400 RPM hard drive and an 7,200 RPM hard drive. I've also noticed there's something called "NCQ" (native command queing), and I'm wondering if that helps either.
The differences are noticeable for things that are disk intensive. Things like loading applications and starting Windows will improve measurably. Loading Photoshop and Illustrator on a 5400 rpm drive is painful (I know, I do it all the time). Once they're open, though, the disk doesn't make a difference to how they perform, though. Likewise, opening large files will also benefit. AirForceElite pointed out that 5400s can be had in larger capacities. Higher data densities improve performance (the data is packed closer together, so the disk head travels over and reads more bits per uinit time). So if sustained reads are important to you (like you frequently open a lot of large files), then a higher density 5400 can give you better performance (and more room to store stuff too). You aren't always disk-limited, though. For example, if you're looking to improve gaming performance, a faster disk isn't going to do a damn thing (other than for stuff like loading levels as Charles noted), and you may want to choose on the basis of cost/megabyte or some other determinant.
Native command queing isn't that big a deal. Pretty much all SATA disk support it now, but it rarely helps much for desktop apps. IDE drives don't support it, but it's really not a big deal. Disk write performance is just about a complete non-issue for desktop systems. Read performance matters more, but NCQ doesn't help all that much with the big killer of disk performance for desktop stuff--latency. NCQ can re-order reads and writes to minimize head travel, but re-ordering a read from ABC to BCA doesn't help if the application really needs A first.