ok, im gonna ask as well about backing up my PS3's HDD.
i know i can back up my HDD on an external HDD. but will i be able to reinstall the back up on my PS3 with a new 1TB HDD?
Yes, you can. You will need it to be formatted as Fat32 for the PS3 to be able to read it.
If your external isn't Fat32, and you don't want to reformat it, you can always:
Format new HDD Fat32 Back up data to new HDD Copy data to your computer Remove old HDD, insert new HDD in PS3, allow PS3 to format new HDD Format old HDD as Fat32, copy backup to old HDD Restore backup from old HDD to your PS3
As for the SATA question yes it looks like it will still work. The PS3 natively supports SATA 1.5 GB/s it would seem but SATA II 3.0 GB/s drives are backwards compatible but will run at the 1.5 GBs speed. However, the drive will still perform better than a standard 5,400 rpm drive.