2010-04-16, 09:52 PM
Portability:
2.5 inch external harddrives allow more portability, since it doesn't need external power.
3.5 inch external harddrives require external power source, so less portable.
Bang/Buck:
2.5 are more expensive per unit of space than 3.5
Performance:
most 2.5 are slower than 3.5. Though this totally depends on the harddrive themselves.
ATA/eSATA/SATA/wtp
These days, SATA is the standard. So when you look for a drive/enclosure it's almost guaranteed that it'll be SATA to SOMETHING.
The SOMETHING can be USB 2.0, 3.0 (of course all backwards compatible) and eSATA and firewire. USB 2.0 is the most popular choice right now, with more computers coming standard with eSATA ports, you might see more of this in the future (because eSATA has a larger theoretical bandwidth than USB 2.0, one might argue that 3.0 is better than eSATA but it doesn't matter due to the harddrives being the bottle neck).
That SOMETHING can be two or more things. Example: a enclosure could have multiple connectors (eSATA, USB, firewire) for compatiblity.
When it comes down to buying a already made External harddrive or a DIY one, the DIY ones are often cheaper and offers more peace of mind, since you know the kind of harddrive you've used.
2.5 inch external harddrives allow more portability, since it doesn't need external power.
3.5 inch external harddrives require external power source, so less portable.
Bang/Buck:
2.5 are more expensive per unit of space than 3.5
Performance:
most 2.5 are slower than 3.5. Though this totally depends on the harddrive themselves.
ATA/eSATA/SATA/wtp
These days, SATA is the standard. So when you look for a drive/enclosure it's almost guaranteed that it'll be SATA to SOMETHING.
The SOMETHING can be USB 2.0, 3.0 (of course all backwards compatible) and eSATA and firewire. USB 2.0 is the most popular choice right now, with more computers coming standard with eSATA ports, you might see more of this in the future (because eSATA has a larger theoretical bandwidth than USB 2.0, one might argue that 3.0 is better than eSATA but it doesn't matter due to the harddrives being the bottle neck).
That SOMETHING can be two or more things. Example: a enclosure could have multiple connectors (eSATA, USB, firewire) for compatiblity.
When it comes down to buying a already made External harddrive or a DIY one, the DIY ones are often cheaper and offers more peace of mind, since you know the kind of harddrive you've used.