SATA 2.5" vs 3.5": Interfaces the same ?

A seemingly simple question:

wrt SATA interfaces on 2.5" and 3.5" hard disks: are they physically the same ?

Can I use a device that says for "SATA 2.5" disks" on "SATA 3.5 disks" just by swapping the disks ? (I believe that whatever the SATA standard is, I,II or III, as they are 'downwards compatible' so there's no need to worry about that. Also I'm not including eSATA in my question)

It certainly used to be the case that the pin-outs were the same, but now some devices seem to be described as "for SATA 2.5" disk drives", and I was wondering if there was physical difference now, or it was just highlighting that the product could be used with ever popular laptop disks (at the expense of also saying that the product could be also used with 3.5" disks) ?

Also, what is 'bulk transfer mode' ? Does its use preclude any other useful transfer mode ?

Dumb_Question
18.August.2013

 

The connectors are the same in the 2.5" and 3.5" SATA drives, but you usually can not put a 3.5" drive where a 2.5" is needed, like a laptop. 2.5" and 3.5" are actual sizes of the drives. eSATA connectors are not the same as regular SATA.
http://en.wikipedia.org/wiki/Serial_ATA

 

As stated, the connections are the same.

Companies like OCZ supply adapters with the drives they sell so a 2.5" drive can be placed in a 3.5" bay.

This is especially useful since most SSDs are 2.5" models. Conflict does arise when things like netbooks can have a drive which is 1.8" wide. That's why they mention the size factor you are referring to.

Almost forgot. Bulk transfer mode is for the purpose of moving very large files, using all the bandwith available. This is a useful feature, especially for an external/internal storage drive, or drives utilizing data over a server system.

 

I had forgotten another important difference - the connectors are the same physically and may also be electrically, but I infer that a 2.5" (such drives can be connected to 5V USB only, no 12V, tho' they may need power from 2 USB 2.0 ports) drive does not need the 12V supply. In a proper cable it will of course be wired up.

Dumb_Question
19.August.2013