DISK Data Transfer Rate

Question

A disk unit has 20 recording surfaces. It has a total of 14,000
cylinders. There is an average of 400 sectors per track and each
sector contains 512 bytes of data. Find the storage capacity of the
disk unit. If disk rotates at a speed of 7200 rpm then what is the
data transfer rate in bytes per second?

 

Do we need to multiple answer with 20 assuming that all surfaces are transferring data in parallel or not?I have a solution manual but in that it is not multipled with 20 but most of the questions in Go i have seen which multiplies it with no. of surfaces.Please clarify?

Comments

It would be multiplied when we have 20 read/write heads.If just one read/write head no need to do that

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i think by default we should consider multiplying with the number of surfaces

questions ive come across till now hasnt mentioned anything regarding the number of read/write heads explicitly

 

correct me if i am wrong

Answer 1

The Capacity of the disk is = no. of surface *Total no. of Track. * no. sector * size of a single sector

the Data Transfer of in 1 Sec =

time for i 1 rotation =60/7200=6/720=1/120 sec

in 1 sec disk rotate =120 time 

than data transfer rate =120*size of one track