Quick question (computer related).....

M

MBH_14

New member
Joined
Feb 5, 2005
Messages
20
You buy a PC with a 2 GHz processor and a 60-ns memory. How many processor cycles does it take to access the memory in such a system?

Is this as easy as i think it is? All i did was multiply 2 by 60 to get 120 cycles. Is that correct, or am i missing something?

Also, this is just a general question:

A computer system with 2 GHz processor always executes all programs faster than a computer system with 1 GHz processor. Is this true or false?

I am thinking this is false, am i correct in saying this?

Thanks for any help or confirmation!
 
I think we haven't enough information. The actual operating speed of the external bus is as important as anything.
 
A computer system with 2 GHz processor always executes all programs faster than a computer system with 1 GHz processor. Is this true or false?

I am thinking this is false, am i correct in saying this?
Click to expand...

Well I think the answer they want is false. You can tell by the wording of the question actually, because they say always and all. The idea is that a faster processor does not equate to a faster program necessarily.

This is why I don't like true and false questions though. If it were open ended you could explain that 99% of all programs would see some performance gain at least, even if it is very small. You could then explain why it won't be a 2x performance gain, but usually somewhere in between. However, their point is that other factors (hard drive access, memory speeds, bus speeds, video cards, etc.) can bottleneck performance such that the extra GHz won't matter. You can argue that there is always *some* part of the program that would execute a few ms faster on a faster processor, but I think you have to read into this question to figure out "what they mean" and not get too technical.
 
You buy a PC with a 2 GHz processor and a 60-ns memory. How many processor cycles does it take to access the memory in such a system?

Is this as easy as i think it is? All i did was multiply 2 by 60 to get 120 cycles. Is that correct, or am i missing something?
Click to expand...

Well it would really help if we were in your class so we knew how in depth this question is supposed to be, but if it is "that easy," then you are correct.

A 2GHz processor performs 1 instruction in one two-billionth of a second (1/2GHz). Therefore in 60ns (60 billionths of a second) you would complete 120 instructions.

Of course, factors like the bus speed would obviously come into play here I think... so this is a perfect-world kind of answer.

Ted
 
thanks Ted. Thats what i figured. This is an introduction to engineering class, and we really havent gone into much detail about bus speed, etc. So i am thinking that this question was not meant to take into account all of the other variables that could make a difference. Thanks for your help!
 
You must log in or register to reply here.
Top