Largest Internal Drive?

What’s the largest capacity internal drive that I can install in an AppleTV?

It’s ATA, correct?

It’s 2.5" drive, correct?

Do 2.5" ATA drives come in a larger capacity than 320 GB?

I’m thinking about this drive: http://eshop.macsales.com/item/Western%20Digital/WD3200BEVE/

Thanks!

As far as I know the largest 2.5" ATA drive is 320GB.