#5

(a) Consider a hard disk with 9000 RPM and 3 single-sided platters. Each surface has 200,000 tracks and 1500 sectors per track. (For simplicity, we assume that the number of sectors per track does not vary between the outer and inner area of the disk.) Each sector has 512 bytes. What is the capacity of the disk? What is the maximum rate at which data can be read from disk, assuming that we can only read data from one surface at a time? What is the average rotational latency?

(b) Suppose we have the same disk as in (a), where the average seek time (time for moving the read-write arm) is 5ms. How long does it take to read a file of size 8 KB? How about a file of 800 KB? How about a file of 16 MB? Use both the block model (4KB per block) and the latency/transfer-rate model, and compare.