wanting a new internal HD

I've got a G4 and am wanting to put a second, larger hard drive inside. The physical specs are spelled out in my Mac docs, but I'm looking at hard drives and the spec for width is 3.9 inches. The drive I'm looking at says it's width is 4.0 inches. Will this slight difference in width render it unable to fit in my G4 carrier?

Also, the drive indicates it is "SATA". What's the dif between SATA and ATA?

Can you be more specific on what G4 you have? (Cube, iMac, eMac, PowerMac?)

Regardless of physical dimensions, your G4 will only take an PATA (ATA) drive, unless it's a powermac, in which case you could buy a SATA controller and plug in the drive. I would recommend sticking with PATA as I haven't seen a significant performance upgrade doing this.

This http://mactracker.ca/ is an invaluable assistant in almost anything Mac. Check your G4 specs and compare with what Mactracker tells you about its upgrade potential, eg. drive type and size.

Physical case width is generally standardised for 3.5" drives. The 3.9" vs 4" may be due to a rounded figure.