Difference between 3.5" and 2.5" HDD

Hi guys,

I tried googeling but without any results (and I just like starting topics ).
I'm considering replacing the HDD from my 13" MBP with a SSD, so I would need an external HDD for my pictures, movies, music etc. I was just looking and I'm wondering if external 3.5" external HDD's need a power supply or do they draw their energy via the USB like 2.5" HDD's do? Is there a difference between 2.5" and 3.5" drives? The 3.5" are bigger and have more capacity for less dough (which is always a good thing), but I'd like my setup to be portable. Do 2.5" drives come with 7200rpm as well?
If anyone could recommend me a good SSD (one that won't break down on me), feel free to do so. I surely won't need more than 120GB.

And while I'm at it, what's the difference between internal 3.5" and 2.5" drives? Sure enough they won't bother you once they're inside, so why would I want a 3.5" over a 2.5" (or vice versa)

Regards from Holland!

All 3.5" externals I've come across require a power supply while the 2.5" ones don't (I've got a Western Digital Passport which I use). You can get 2.5" 7200 RPM versions, at a cost, but I never tried one before.

As for SSD drives, never used one either so can't comment, but I imagine any from the major drive manufacturers are fine.

also, the difference between 3.5 and 2.5 internals. You aint going to fit a 3.5" drive in a laptop or enclosure designed for a 2.5". Likewise a 2.5" won't fit into your standard computer tower case (maybe you can buy a bracket to fit in a 3.5" bay but why would you bother?).

gep01 wrote in post #11993265
also, the difference between 3.5 and 2.5 internals. You aint going to fit a 3.5" drive in a laptop or enclosure designed for a 2.5". Likewise a 2.5" won't fit into your standard computer tower case (maybe you can buy a bracket to fit in a 3.5" bay but why would you bother?).

My last case has a slot for hotswapping a 2.5 built right in the front. I have no use for this but I liked the case so I got it anyway. I can't really see a use for it. I rather that they would have included another fan instead

I have a couple of passports and sometimes they get flaky when used with my laptop, like not getting enough power to run them. No way it will run both at same time.

TijmenDal wrote in post #11993229
I'm considering replacing the HDD from my 13" MBP

Which MBP do you have (i.e., what ports)?

All 3.5" drives require a 12V line, and that is not provided by USB or Firewire buses. Those only provide 5V (or 3.3V), which is sufficient to power 2.5" drives.

Yes, up to 750 gb. The 1 tb drives are 5400 rpm. Spindle speed is irrelevant for external drives because the bottleneck is the connection to your MBP (FW800 > FW400 > USB2).

Do you use your optical drive? If not, I'd suggest you pull it and put and keep your internal HD and add the SSD. You can always buy an external optical drive for the occasions when you need one. They typically connect by USB2 and are very inexpensive. You should only use SSDs with Sandforce controllers, such as those from OWC or OCZ.

Laptops take 2.5" drives, not 3.5" drives. You can buy external enclosures for 2.5" drives that are bus powered, but not 3.5" drives. Those all require their own power supplies.

Tony-S wrote in post #11994593
Do you use your optical drive? If not, I'd suggest you pull it and put and keep your internal HD and add the SSD..

^^^ This.
http://eshop.macsales.​com …ld%20Computing/​DDAMBS0GB/

René Damkot wrote in post #11994680
^^^ This.
http://eshop.macsales.​com …ld%20Computing/​DDAMBS0GB/

Holy, that's awesome! The thing I really wouldn't like about getting a SSD would be that I'd have to carry around an external hard disk all the time, but now I can have a 640gb HDD and 120gb SSD or so, which would be enough (for the moment at least )

Tony-S wrote in post #11994593
Which MBP do you have (i.e., what ports)?

All 3.5" drives require a 12V line, and that is not provided by USB or Firewire buses. Those only provide 5V (or 3.3V), which is sufficient to power 2.5" drives.

Yes, up to 750 gb. The 1 tb drives are 5400 rpm. Spindle speed is irrelevant for external drives because the bottleneck is the connection to your MBP (FW800 > FW400 > USB2).

Do you use your optical drive? If not, I'd suggest you pull it and put and keep your internal HD and add the SSD. You can always buy an external optical drive for the occasions when you need one. They typically connect by USB2 and are very inexpensive. You should only use SSDs with Sandforce controllers, such as those from OWC or OCZ.

Laptops take 2.5" drives, not 3.5" drives. You can buy external enclosures for 2.5" drives that are bus powered, but not 3.5" drives. Those all require their own power supplies.

Thanks for all the answers, really helpful! I don't really use the optical drive, I maybe 5 times a year - if that, haha! And I guess within 2 years cd's/dvd's aren't even made anymore, and I'd surely wouldn't use my drive. I happened to use it yesterday to install DPP (which I didn't really like)