Ace academy test series question

Question

Suppose that a bus has 16 data lines and requires 4 cycles of 250 nsecs each to transfer data. The bandwidth of this bus would be 2 Megabytes/sec. If the cycle time of the bus was reduced to 125 nsecs and the number of cycles required for transfer stayed the same what would the bandwidth of the bus?

A.      1 Megabyte/sec                                      B.      4 Megabytes/sec

C.      8 Megabytes/sec                                     D.      2 Megabytes/sec

Comments

data lines....

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Answer given is 2 Megabytes/sec. Thank you @hs_yadav. I understood now.

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Answer should be 4MBps. Can somebody please confirm this?

Answer 1

@hs_yadav

I belive given question was talking about time in nano second not in seconds.

2 Megabytes/sec BW it is taking 1 micro second ( 4*250ns) which is greater than 125ns

in my opinion answer should be = (4*125 ) 0.5 micro second so it will 16/0.5 usec 

Please clarify  if my thought is wrong

Comments

Here they asked if cycle time reduced to  125nseca than bandwidth????

Bandwidth = Rate of data lines * Number of data lines

 

 

             

 

 

= ( 1-bit/ 4*250ns ) * 16 = 16-bits / 4*250ns =0.016*1000000000sec=16Mbytes/sec=16/8=2MBps

 

If 125nsec cycle time than =16/4*125=4 MBps

How it is 2MBps?? Plz confirm this..