CS251 : CS251-PPT#10-W13.pdf
Document Summary
[with material from computer organization and design by patterson and hennessy, and digital design and. Computer architecture by harris and harris, both published by morgan kaufmann] Additional notes on memory-mapped input and output. There are 10,000 to 50,000 tracks per surface d. Higher density disks have it di k h higher density of tracks. Each track typically contains 100 to 500 contains 100 to 500 sectors. Sectors are typically 512 bytes in size (can range to. Queuing delay if other accesses are pending. Seek: move the head over the required track. Seek time: delay required to reach the required track. Rotational latency: delay required to reach the required sector g. For 5,400 rpm hdd, average latency is 5. 6 ms. For 15,000 rpm hdd, average latency is 2. 0 ms y. Data transfer: delay that is a function of the sector size, the rotation speed, and the recording density of the track of the track.
