Slowing down CPU speed

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  I have an HP ze1230 laptop with AMD Athlon XP 1300+. The machine is
giving random strange answers to some numerical problems. I checked the
same program on 3 other computers and none had any problems.

  The machine is running hot. I placed it in a fridge but made no
difference. I want to try out slowing it down and see if the problem
will go away. How can I slow down the clocking speed?

  Any suggestion is greatly appreciated. Is there a place I can get a
cheap older CPU? ( AMD Athlon XP 1300+.)



Re: Slowing down CPU speed

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You can test your CPU with prime95. Just run the torture test.
Have you tried cleaning the laptop ? Remove any dust etc. that has
built up.
Do you know how hot the CPU is ? Motherboard monitor may tell you.
Ebay may be a source if it is the CPU.
If you give your location, you may get more advice.


Remove the dross to contact me directly

Re: Slowing down CPU speed wrote:

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I downloaded a manual, and page 27 says there is a diagnostic
tool (eDiagTools). I have no idea what the tool tests, but it is
free, so why not.

After running that tool, here are some other tools you can try.

1) memtest86+ ( ). This program tests all the
   memory on the computer. There is a version that will format
   a test floppy for you, and another version you can burn to
   a test CD. The test floppy version will boot the machine,
   and a 640x480 diagnostic screen will appear. All the test
   to run for two complete passes. This could take a couple
   hours. Any errors at all, is unacceptable. The main value
   of memtest86+, is finding consistent "stuck-at" errors in
   the memory, and other tests actually do a better job of
   finding random errors.

2) Prime95 "torture test" ( ). Prime95 is a
   numeric test, where the answer is known. The program basically
   uses a chunk of memory (the size of which can be set by the
   user). If a processor is unstable, Prime95 will stop with an
   error in seconds. If the program will pass an overnight run
   without errors, then chances are the processor and memory
   are in good shape.

Since it sounds like the computer is thermally compromised, before
using Prime95, I'd want a temperature monitoring program running
on the laptop at the same time. That will allow you to monitor
how hot the processor gets at full CPU load.

It could be that some part of the cooling system is clogged with
dust, and the machine is overheating. In which case, a cleaning
may be called for.

I don't know how easy it will be to find an exact replacement
processor. It would be tempting to put something more recent
in it, but I doubt the BIOS would recognize the processor.
Ebay might be the only way to find one.

Get a copy of CPUZ, and note the particulars for the processor.
It is either that, or remove the heatsink from the CPU, and
read the label on the processor - the OPN code should be on there.

This page has some 1333MHz processors on it, but I don't know
if your processor is some kind of mobile chip, or a regular
chip. i'm surprised a page like this is still around.


Re: Slowing down CPU speed

Paul wrote:

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That *might* only exercise the integer units, not the floating point units.

Clearly primes and composites numbers are integers and so not floats.
But if the the numbers the OP are having problems with are irrational
(i.e. you need to use a floating point processor to represent them), the
test might not be appropriate.

However, the test might well use floats, as testing for large primes is
normally a probabilistic test. (I suspect that means you need irrational
numbers, but I don't know, as I have never looked at the details).

However, if one needs to use arbitrary precision floating point
arithmetic (i.e. highly accurate), then that too would be implemented in

So such a test might not be appropriate. Sure I know a lot of people use
it, but it was written to test PCs for the purpose of evaluating if they
were up to the job of prime number testing, not as a general test tool
for extensively testing PCs.

Dave K     MCSE.

MCSE = Minefield Consultant and Solitaire Expert.

Please note my email address changes periodically to avoid spam.
It is always of the form: month-year@domain. Hitting reply will work
for a couple of months only. Later set it manually. (Web based Mathematica front end)

Re: Slowing down CPU speed

"Dave (from the UK)"
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implemented in


The portion of Prime95 I use to test PC processor & memory is called
 torture test.
I don't think it has anything to do with primes.
The description states "In-place FFTs (max heat, power consumed,
some RAM tested)".
When I was doing FFTs they used floating point ops intensively.
I can't guarantee that Prime95 does - that's not particularly
important to
What Prime95 torture test does for me is that it's the best test tool
I have
for heating up processors, while at the same time checking that they
producing the expected results.
A couple of passes of Memtest86, an overnight run of the torture test
I feel reasonably happy that the system processor & memory are OK.


Remove the dross to contact me directly

Re: Slowing down CPU speed wrote:
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hello bro, i had the same trouble with a customer regarding the same
problems : Acer Aspire 5002WLCI... AMD turion 64, this tech need a
memory of 400 MHZ Acer they installed 2X 256MB DDR PC2700 333MHZ, this
was making the system getting hotter, and the fan was shut instead of
always on. They say it was repaired but not. we found how to corrected,
putting a PC3200 DDR one stick of 512MB, we activated the fan, we
download the cpu driver, we managed the energy to be better controlled...

  go to , check the bus speed of your memory if is
lower then get memory at the same speed then the board, download drivers
from to help the cpu working better, see if you can activate the
fan if is off, then its ok keep it on. // ... see if your
battery still good.

Laptops as Acer, Compaq, HP, Dell ... they cheat inside laptop they put
normaly like acer cheap chipset SIS, what the hell is this chipset,
Event ethiopia will refuse it. depend what you wanna spend also still
its not nice to play us.

IF not replying Happy independance day to all American, salut all bro

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