Question

A 32-bit computer has two selector channels and one multiplexor channel. Each selector channel supports two hard disks and two DVDs units. The multiplexor channel has two printers, five VDT terminals connected to it. Assume the following transfer rates.

Disk drive 800 Kbytes/s
DVD drive 700 Kbytes
Printer 10 Kbytes/s
VDT 2 Kbytes/s

Estimate the maximum aggregate I/O transfer rate in this system.

Answer 1

Maximum Aggregate I/O Transfer Rate = 1630kb/s

Explanation:

Given

Transfer rate of

Disk Drive = 800Kb/s

DVD Drive = 700Kb/s

Printer = 10Kb/s

VDT = 2Kb/s

Units

DVD = 2

Hard Disk = 2

Printers = 2

VDT Channels = 5

Only one device at a time can be serviced on a selector channel

Both cannot be active at a time

So, the device with higher transfer rate will be granted access (Disk Drive, 800Kb/s)

Maximum aggregate I/O transfer rate in this system is calculated by:

Summation of transfer rate of each device

= 800 * 2 + 2 * 10 + 5 * 2

= 1600 + 20 + 10

= 1630kb/s