IBM Hard drives for notebooks

[adam4925]

I was looking at the IBM site and was designing a PC when it asked...

Do I want

A) 40GB High Speed Ultra ATA/100 Hard Drive
B) 40GB Ultra ATA/100 Hard Drive
C) 80GB ThinkPad Hard Disk Drive

What is the difference (especially between A and B) and is there anything else special about the 80GB drive except that it can hold a lot of junk? Thanks.

 

[Shivatron]

All three of these drives share the same form factor and interface. The only difference is rotational speed...

A) 40GB High Speed Ultra ATA/100 Hard Drive

This is the 5400r/min varient of hard drive "B" below. Out of the three, it would be my choice because it has higher transfer rates than a comparable 4200r/min drive.

B) 40GB Ultra ATA/100 Hard Drive

This is the 4200r/min varient of hard drive "A" above.

C) 80GB ThinkPad Hard Disk Drive

This is a 4200r/min drive.