Impact of Technology

• CPU and Disk improves at a different rate

  • Performance gap

• DRAM capacity growth

  • Size of file cache increases
  • Disk traffic is becoming dominated by writes
  • Write-behind?

Previous slide

Next slide

Back to first slide

View graphic version

Disk Performance: capacity + cost versus performance

performance:

access time : 7% year

transfer time: depends on RPM and BPI.

RPM doubles every 4 years

BPI shows 40% increase over years

Increase in file cache:

disk traffic change - read workload absorbed / all writes

ability to buffer writes - improves write efficiency