[Bruce Abbott]

Originally Posted by pandy71

IMHO statistically 2.5" failed more frequently - this my impression - comparing population of 3.5" and 2.5" this was obvious - perhaps due application, 2.5" worked in mobile application where 3.5" static.

My experience was the opposite, perhaps because desktop PC maintenance was a major part of my business. But most of the hard drives I used in my own PCs also failed.

2.5" drives usually park their heads after a short delay, and spin down after a few minutes. This is done to lessen the chances of bumping the computer causing a head crash, and to save power. Due to the much smaller mass of the platters and head mechanism, a 2.5" drive can spin up and be ready to go in less than a second, making this operation viable.

Statistically 2.5" were less popular than 3.5" (even due simple higher price vs capacity), 3.5" 120MB price was similar to 40MB 2.5".

This is true. However cheap 3.5" drives generally weren't as good IMO. One egregious example was the Quantum 'Bigfoot' - a very slim 5.25" drive. Cheap, but not up to Quantum's normal standard. Seagate, Maxtor and Western Digital also had some stinkers.

Luckily (actually by design) the Amiga didn't need as much storage space as a PC. By the time you put DOS and Windows on a 20MB hard drive there was hardly any space left, and almost all PC games had to be installed on the hard drive so you needed that extra space!

This depend on manufacturers - for Conner differences are significant:

C P - 3 0 1 2 4

Rotation   RPM      4542
Seek time   / track  14.0/ 3.0 ms 
Data transfer rate    3.000 MB/S int
                            6.000 MB/S ext

C P - 2 0 4 4

Rotation   RPM      3486
Seek time   / track  14.0/ 3.0 ms
Data transfer rate    1.500 MB/S int
                            4.500 MB/S ext

126MB vs 42MB not fair. Let's compare apple to apples shall we?

C P - 3 0 4 4    CONNER
Form                 3.5"/SLIMLINE
Capacity 43 MB 
Rotation   RPM      3557
Seek time  / track  25.0/ 8.0 ms 
Data transfer rate    1.500 MB/S int
                      4.000 MB/S ext

Same data transfer rate, much slower seek times on the 3.5" drive.

Power consumption differences was less important for customers in desktop applications.

It mattered on the A600 and A1200.

Even on a desktop machine it can be an issue. 7200 rpm drives tend to run much hotter. If you have two drives close together they can overheat. I often had to put extra case fans in PCs to keep them cool.

BTW I am currently using a 127 GB 2.5" drive for backup storage in my Windows XP box because I happened to get one from a dead laptop (which sadly tend to die more often than hard drives these days!). I also have a couple of nice 4GB 2.5" drives from old Pentium laptops that I bought just to harvest the drives from. One of these is earmarked to go in my A600.