General discussion

processor speed brainteaser

For a math book problem my wife is working on, we're trying to get a comparison of how fast two different processors can process a megabyte of data. We've searched processor specs and different side-by-side comparisons but haven't found anything that puts this in those simple terms, which is what we need for this general book. Is there anyone who can point us to a formula for taking the gigahertz capabilities of a given processor to get the seconds per megabyte processed?


Gerry L.

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amdahl might help us

Amdahl's Rule Of Thumb is that 1 byte of memory and 1 bit per second of I/O are required for each instruction per second supported by a computer. This also goes by the title Amdahl's Other Law. (from Wikipedia, the Free Encyclopedia)

so 1 megabyte of data would = 10^6 (1,000,000) bytes

you'd have to derive the I/O bandwidth on the mainboard, both in terms of RAM and CPU FSB (go with the weakest link for good measure)

and then look at the MIPS or GFlops figures for a given processor

honestly I'm guessing theres going to be a basic derived formula in the book, or at least a guideline, given that I've never seen a text book be so ambiguous

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you're right, it is very ambiguous

i should clarify that it's not a math problem we're trying to answer. we're doing research to develop a new problem as an update to a previous edition of the book. the previous version had a comparison between a 2.53-gigahertz celeron processor and a pentium 4 3.0-gigahertz processor, with the celeron taking 45 seconds to process a megabyte of data and the pentium taking 30 second. we don't know the source of the original data but need to update it.

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How are you testing this?

What OS are you using?
The fewer resources that an OS uses, the faster it can process data. If you go for something such as plan9 or minix, you will get a faster response time than if you went with Windows or MacOS?.
Test the formula with every system available and then release the results, doing such with only one system is biased.

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processing 1mb of what?

different processors have different strengths. for example, amd athlon CPUs have superior floating point processing power when compared to intel processors at the same speed. however, both amd and intel use specialized extensions (SSE) to speed up certain types of calculations.

also, some applications benefit greatly from L2 cache. so a CPU with 4MB of L2 cache will perform better than a processor with 1MB L2 cache in those applications. but for other cache insensitive applications, the extra L2 cache may not influence performance at all.

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good questions

thanks, ramarc and porch-a-geese, for the insights. sounds like we need to define the terms a lot more specifically. we are not doing any of our own testing, though. this is just for a set of facts for a math story problem.

in any case, thanks again for the help.

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not to mention

that various degrees of SSE implementation will provide more speed as well, for example when Intel released SSE3 creative professionals saw incentive to move to Intel, due to the faster rendering of video and higher performance in audio applications

as far as AMD vs Intel clock for clock, they're about the same, to Intel edging out a little faster (based on the Core Microarchitecture, especially if we're comparing Phenom to Core 2 Quad)

but yeah, basically CPUs are very different from one another, and your question is quite broad, I'd either just keep the current question, or spend the hours and hours of research to revise it correctly

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Can you post the original information here?

It would help if we could see it. What your talking about is bench marking but this is not generally expressed in these terms. In fact there are many ways the speed of processors are evaluated/compared.

See this example:

Search "Sandra", this is close to what your looking for. The "overclockers" might be of assistance as well. That's what they do. They have many web sites on the Internet. "Overclockers" should not be confused with "Gamers". Gamers over clock there CPUs to "push" the performance of there PCs so there game play improves. Overclockers "push" there CPUs to see how fast they can make them run, sort of like automobile drag racing.

The truly "big" game is Blue Gene:


This is off the subject but I've been looking for something for some time now, maybe you've bumped into it. There is an overclocker web site that is offering a $100.000.00 prize if someone breaks a certain integer bench mark. They provide a software package I'm looking for. Have you seen or heard of this site? If you would stumble on it during your search please post it here. I've been trying to find this for months.

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I have a computer architecture book that has a chapter on this; You can find it on google book. Look at around page 39-45

Name of the book is: Computer Architecture (A quantitative Approach) By John L Hennessy and David A Patterson.
4th Edition.

Most of the subject are a bit too technical, but those first chapters should help you with your problem. One thing that you have to consider though is that you can talk about the speedup that you gain in terms of performance or execution time. Also, you have to be specific about what kind of data you are dealing with... may be do a comparison of 2 different programs that you can run on both machines. I think generally speaking this subject is too complicated for a math book, you'd be probably better off being more broad when it comes to these kinds of examples.

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Looks like you're out of luck
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Load the formula into the search bar

and see what you get. There are usual scientific notation applications in most word processing programs. Because of it's narrow topic the number of results might be few but might provide some information. Good luck.

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If the above doesn't work, try this.
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Or this

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