※ 引述《aweila75 (David)》之銘言：
: 2.A multiplattered hard disk is divided into 40 sectors and 400 cylinders.
: There are four platter surfaces. The total capacity of the disk is 128MB.
: A cluster consists of 4 sectors. The disk is rotating at a rate of 5400rpm.
: The disk has an average seek time of 12 msec.
: (a) what is the capacity of a cluster for this disk?
: (b) what is the average access time before starting data transfer?
: (c) what is the maximal disk transfer rate in bytes per second?
: 想了很久，算不出來XD，高手請幫忙，感謝您。
(a)4*400*40 = 64000 sectors
一sector的capacity：128MB / 64000 = 2000 bytes
一cluster的capacity：2000*4 = 8000 bytes
(b)（60*1000ms）/ 5400 = 11.11ms
11.11ms / 2＝5.55ms
12ms＋5.55ms = 17.55ms
(c)迴轉一圈所須時間：（60*1000ms）/ 5400 = 11.11ms = 0.01111second
資料量:2000 bytes*40 = 80000 bytes
maximal disk transfer rate：
80000 / 0.01111 = 7200720 bytes/second
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※ 編輯: just1016 來自: 122.127.53.72 (04/22 22:55)