PPT Slide
Cost Evaluation of VM
- Assume memory access time = 200 x 10-9 secs if the frame is in memory.
- Assume that the page fault interrupt handler takes 40 x 10-6 secs to execute it’s code.
- Assume reading the page from the swap partition on the disk takes 20 x 10-3 seconds.
- The disk read time is 6 orders of magnitude larger than the memory access time and will dominate, so we can ignore the time spent executing the page fault handler (it’s 1/500th of the disk read time :).
- The result is that a page fault memory address runs 100,000 times slower than a non-page fault memory address!