Read Computer's speed

[Fred Katzel]

Is there some way to read a computer's speed and so adjust the speed with which a PowerBASIC program runs? I developed a PowerBASIC program years ago on a slow Hz computer then when I upgraded my computer to a faster Hz, I had to build in delays in order to see what was on the screen.

[Eric Pearson]

Not really... But there are a couple of ways that you could handle it.

You could add a "test loop" to the very beginning of your program, and use it to calibrate the rest of your loops. In other words, if the test loop runs in 5 seconds on your old computer and 1 second on your new computer (as measured with TIMER or MTIMER) then you would set a "multiplier" variable to 5 to tell all of your delay loops how long to run. The rest of your delay loops would look like this...

FOR X% = 1 TO (DelayCount * Multiplier)
   'WHATEVER
NEXT

But if you do that, remember that Windows will fool you. If you're running your PB/DOS program on a Windows computer 1) Windows will give more "attention" to your program for the first couple of seconds after your program starts, so the rest of your program will not run at the same speed, and 2) the speed of any program on a Windows computer is dependent on how many other programs are running at the same time, and how CPU-intensive they are. So your program is very likely to speed up and slow down, more or less randomly.

A much better way to "moderate" the speed of your program would be to use TIMER- or DELAY-based delays instead of loop-based delays. That way, your program would delay for a certain number of seconds or milliseconds, instead of delaying for the time it takes to execute a loop a certain number of times, because DELAY is not (very) machine-speed dependent. The resolution of DELAY/TIMER is limited to about 0.05 milliseconds, so it averages 50% of that accuarcy or about 0.1 seconds. In other words, if you write a function and tell it to delay 0.05 seconds, you will actually get a delay between 0.0 and 0.1 seconds, with an average delay of 0.05. The longer the delay, the more accurate (percentage-wise) it will be.

If your program runs on Windows computers the "ultimate" solution would be to convert it to the PowerBASIC PB/CC compiler. The Windows SLEEP function has a resolution of about 10 milliseconds (0.01 seconds), and even more accurate timing functions are available.

HTH.

-- Eric

ADDED LATER: I just re-read your message and I'm not really sure how I got the idea that you were using loop-based delays. Oh well, the info might be useful anyway...

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[This message has been edited by Eric Pearson (edited March 17, 2000).]

[Walt Decker]

There are a number of delay routines in the ABC Archives.
http://www.basicguru.com/abc

Do a search on topics:TIMERS, DELAYS, SPEED and see what you get.

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[Eric Pearson]

Karl --

> Does this hold true if you boot-up in MSDOS mode?

Which part are you asking about?

If you're asking about Windows "fooling you", then No. If you boot into the MS-DOS mode, Windows is virtually 100% out of the picture, so as far as I know apps will run at a constant speed (ignoring disk/network access delays, etc.). And PB/CC console applications can't be run in that mode... they require that Windows be running.

-- Eric

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[This message has been edited by Eric Pearson (edited March 18, 2000).]

[Fred Katzel]

All
I think we have missed the point I raised, namely, is there some way to read the computer's speed. I would like to include it in the program so the program will make the appropriate adjustment.
I am in the process of developing programs that I hope to market and I will need to have them run on various speed computers.
Fred

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[Lance Edmonds]

Ummm... I did? I think you mean Eric.

[Eric Pearson]

Fred --

> I think we have missed the point I raised, namely,
> is there some way to read the computer's speed.

Actually, I think you missed the answer. The answer is No. PCs do not provide any sort of hook, interrupt, API, or anything else that returns the processor speed. Even if they did, it would be meaningless on Windows computers for the reasons that I outlined.

I stand by my previous response: "Not really... But there are a couple of ways that you could handle it."

-- Eric


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[Fred Katzel]

Eric
Thanks, I had seen your answer before but just wondered if anyone else might know a way. But you latest answer is just more complete. Thanks again.
Fred

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[Gary Akins]

Eric Pearson wrote
PCs do not provide any sort of hook, interrupt, API, or anything else that returns the processor speed

Maybe I'm missing the obvious, but... if that's the case, how is it that your BIOS can display your CPU speed on bootup?

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[Eric Pearson]

Heck if I know!

That "CPU Speed" string that you see on bootup is probably hard-coded into the chip's startup code for display puposes. But that doesn't mean that a hook/interrupt/API/etc. is provided to return that string (or the "speed" part of it) to a program. In other words, just because you can do this in a PB program...

PRINT "This is version 1.00 of my program"

...that doesn't mean that the program was written to use that string in any other way. Or that the version number was somehow "measured" and reported by that line of code.

I honestly don't know the answer, but I'm 99.9999% certain that IBM-compatible computers do not provide a method for applications to obtain the "CPU Speed" number at runtime.

-- Eric

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[Greg Turgeon]

Eric is right.  No CPU will report its own speed.  That's because the 
reliable speed of a CPU isn't known until it's tested after being 
manufactured.  If the 450Mhz chip performs reliably at 450 Mhz, it's 
stamped as such and priced accordingly.  If the same chip tests out 
at 400Mhz or 350Mhz, then it's sold as a 400Mhz or 350Mhz.
   
Pentium-class and later CPUs will return their features through the 
CPUID function (the manufacturer's name, MMX or not, etc.), but never 
the processor's speed.  To determine speed, even the BIOS does what 
your program has to do: It tests the CPU itself.  This is why, if you 
set motherboard jumpers incorrectly, your 450Mhz PII will be reported 
as running at 200Mhz or some other speed--which will be correct.  The 
motherboard will be handling the CPU incorrectly, and the speed 
reported will tell you that's happening.  (Of course, if the jumpers 
are correct, then you'll know that your new CPU is probably 
remarked--a lower-speed chip remarked as higher speed by the crook 
who sold it).

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-- Greg
[email protected]

[Ronald Hurley]

Dear Fred

have a look at the url http://members.xoom.com/B_coolWare/

you will find very reliable code in c and pascal for reading all cpu types and speed

also he provides com and exe programs whick can pie output to text file fro reading into dos

I have used this method for 3 years on over 700 pcs on most makes

hope this helps

ron hurley
[email protected]

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