As shrike said, in terms on hard drives that will fit in there, it's a 750GB. I've got a Western Digital 750GB and it's great. However, the 1TB 12.5mm high hard drive CAN fit in the PS3, it just takes a little bit of work, including removing the drive caddy. Look it up on Google. And finally, if you want something bigger, like a 2TB, you'll have to go up to a 3.5" hard drive using SATA extenders. This makes it so the hard drive has to be external. But in terms on actual capacity limit, we don't know yet. I know that 2TB will work for sure.