Phoenix said:
Microdrives do 10-33MB/sec. You'd need an Extreme SD card (20MB/sec) just to get close.
You sure it's not 10-33 Mbit/sec? which is 1.2-4.2 MB/sec. The fastest one I can find so far for Microdrive is 4.9-9.4 MB/sec. The 9-12MB/sec that I quoted above are the 66x-80x SD cards. The extreme SD card are 133x which is 20-23MB/sec for sustained transfer rate.
The reason they are used is speed as well as price. You'd have to throw one AT the ground to actually damage it. It they were that easy to damage or wear out, they wouldn't be used in portable electronics such as iPods
They will still eventually wear out. It has moving parts and uses magnetic platter. It should have a lifespan similar to HDD. Most flash media have lifetime warranty on them.
edit:
I checked and found this for a microdrive.
http://www.memorysuppliers.com/hi4gbmi4cofl.html
Media transfer rate 57.1 - 97.9 Mbit/sec (max)
Interface transfer rate 33 MB/sec (max)
Sustained data rate 4.3 - 7.2 MB/sec
Big difference between interface transfer rate and Sustained data rate huh?
edit 2: Fastest microdrive I found so far:
http://www.photoalley.com/webapp/wcs/stores/servlet/ProductDisplay?storeId=10201&catalogId=10001&langId=-1&productId=13254256
Media transfer rate (Mbits/sec) 67 125
Interface transfer rate (MB/sec, max) 33 Ultra DMA mode-2 (True-IDE mode)
Sustained data rate (MB/sec) 4.9 - 9.4
I think you got interface speed with sustained speed mixed up.