Was talking abt the last 2 years..
HDD now and HDD 2 years ago got double the performance?
5 years ago.. server spindle is already 10krpm.. now, main stream desktop and laptop HDD still 5400rpm, 7200rpm? WD got a 10krpm I guess.. but that was since 2 years ago?
How much increase in transfer speed for the past 2 years?
The one BIG improvement, that we all can see, is the increase in capacity and lower costs..
However, we're talking about performance/speed here, not capacity..
In Year 2000,
http://www.xbitlabs.com/articles/storage/display/hdd-roundup-2.html#sect9
Quick Facts, Ultra ATA 100 has a max interface speed of 100MB/S. The IBM 75GXP that was test is a 20GB model has a Intel IOMeter (file server) linear read @ 68MB/s and Max IOPS of 368.
Fast forward to today in 2011, 11 years later. Following moore law of 2 years for double the performance. so in between, it should have double the previous performance 5 times, or 2*2*2*2*2 or 32times more than the IBM 75GXP. This should gives us a product that has a
- Interface speed of 100MB*32 = 3.2GB/s (achieved today)
- Read speed of 80MB/s * 32 = 2.176GB/s (considering the fastest single SSD performance... nope.. if you consider single hdd, its worst.)
- IOPS 368 * 32 = 11,776k (a vertex 3 240GB gives 40k, so its achieved today, the fastest SAS harddisk gives 398IOPS, so its a miss)
- Size? 20GB * 32 = 640GB (easily met by all hdd and SSD, less the price consideration)
So did Harddisk technology improve as much as its other counterparts.. I would say generally, its more miss than achieved.