Ocing only by increasing the multiplier

Hi there.
I've an AMD Athlon Xp 2500+ cpu and was wondering if it was possible to oc it to 2.5 GHz only by increasing the multiplier?

Yestarday for the first time i decided to go to my bios and change the multiplier to 13 which change my cpu speed to 2.1GHz, i left the rest on auto(the Vcore setting change automatically from 1.65 to 1.80). Temp. increase about +4 C. and windows xp booted fine but since i'm planning on buying more fans soon i changed it back to 1.8GHz.

The reasing i'm asking if it is possible to increase only the multiplier(to 15 or 16) is because i'm not sure about increasing the fsb.......do i increase only the fsb or do i have to change other settings when increasing the fsb?

Any help would be appreciated.

Thanks.

gio.


p.s. i have an A7V8X-X motherboard and 256mb pc2700.

Your desktop Barton is probably capable of 2.2 GHz with stock cooling.

If it's unlocked, it's best to lower the multiplier and up the FSB gradually, in your case you should be able to get to high 180s FSB.

Then up the multiplier and expect 2.2 GHz with stock cooling and with increased voltage...

Thanks for the reply.
So when increasing the FSB from 166(i think) to gradually 180 nothing else gets change right(besides the vcore)?

Also when you say to "lower the multiplier and up the FSB gradually".....is that lower the default multiplier(in this case 11) to 10, etc and then up the FSB?

Thanks.

gio.

Yeah, MHz speed = FSB x multiplier
but it's best to have higher FSB x lower multiplier then the other way around.

In your case you don't have a PCI locked mobo so I would recommend 190 FSB at the most.

Then if you have no problems with higher FSB, up the multiplier.

With stock cooling, you should hit 2.2 GHz.

In addition to increased Vcore, increase Vdimm RAM voltage a little.
You may need to go as high as 1.8 or 1.85 volts but watch your temperatures as they'll go up with increased voltage.


Use Prime95 Torture test like so:
To test the stability of overclocked CPU, download the latest bug fixed version of Prime95:
http://www.mersenne.org/freesoft.htm

Double click on PRIME95.EXE to start the program.

Just Stress Testing (if prompted) > OK >
Options > Torture Test > Blend (if prompted) > OK


The program should not give any errors.
It may be necessary to run the program 12-24 hours to make sure an overclocked system is stable (no program errors displayed).


If you get errors only after several hours, this is a result of slight instability because the system is running with little or no margin. It's stable enough to boot and to be moderately stressed, but as soon as the system is under enough load to go over that critical point, it will freeze. To be 100% stable, Prime95 should run 12-24 hours without any errors.

The point of testing is to see if you get errors or not thus testing the stability. The meaning of errors themselves is not as important.


Running Prime95 Torture Test for 5 to 30 minutes is enough to get a feeling about general stability. If it seems to be stable, increase the FSB (with 0.025V Vcore increase if needed), or increase the multiplier by 0.5.

Reboot and run Prime95 Torture Test for 5 to 30 minutes and repeat this until the Program displays errors.
It's then time to back down and repeat the Torture Test until there are no errors for at least 12 hours.

It's OK to use the computer while Prime95 Torture Test is running in the background.


After finding your stable point you may want to then retest by going to the Advanced section, setting the password to 9876 and then setting Priority to 10. (You won't be able to use your computer while Priority 10 Prime95 Torture Test is running, but it'll confirm your system stability.)

Use 3DMark to test video card stability.

Ok Thanks again for all the info.

Hi there.
I reached 190/38 FSB and a multiplier of 12 with a vcore of 1.75. Run prime95 for 10 minutes(i know lol) and gave me no errors....can anything wrong happen to my pc without testing it for stability with prime95 for 10 or 12 hours?......btw i can't change Vdimm RAM voltage.....motherboard doesn't have that option.

Also when running prime95 my v rails are as follow:+12V 12.544(highest), +5V 4.73(lowest), VCore 1.744 and +3.3V 3.2....and when idle: +12V 12.16, +5V 4.865, VCore 1.728 and +3.3V 3.216 are these numbers good?........my 330W psu recently died(i remember that before it went out my +12V reached 13.4 or something) and i bought a Raidmax 420W psu.

You're doing 2.3 at 190 x 12, that's nice.

If you can't do it day time, run the Torture test overnight to make sure it's stable but it seems you should be all right.

If you get errors, increase your voltage a little and retest.

Hi there.
Sadly i got an internet explorer error while browsing the net and i got another error while playing half life(it close saying unknown error). Right now i'm considering whether to stay @166 x 13 with vcore of 1.65 or 190 x 12 with vcore of 1.75 or above.
Btw. are my v rails ok while idle and running prime95?

Thanks.

gio.

you v rails look good.


Stability testing is a personal preference. Some people don't care if thier system is unstable and some are fanatical about stablity testing. I would have to say let it prime for a minimum of 3 hours. Then you will probably be ok for just gaming or surfin gthe web. If you are going to fold or crunch seti or do some other distributed project I'd Prime for at least 12 hours(overnight) or more.

What are your temps?> idle/load

Hi there.
I'll only be using the computer for gaming and some microsoft office tasks. My temps are 39 C cpu and 34 C motherboard while idle and 42-43 C cpu and 36 C motherboard while playing games or running prime95........my volcano 9 is running at 4300 rpms and the max it can run is at 5400.

Thanks.

gio.

Well your temps look good enough so thatr you can bump your Vcore up a notch or two to get it stable.