Why can't I overclock?

[PizzatheHut06]

I've heard neverending stories about people overclocking their AMD Athlon XP 2500+'s to 3200 speeds with no trouble. When I try to bump my FSB up to 200 MHz, freaking windows won't load. Why is that? My voltage is 1.7, I have good cooling, and I've talked to tons of other people with my same hardware that can overclock fine. What gives?

 

[DJ-CHRIS]

Try bumping up your voltage a bit more if you have good cooling.

Usually only the mobile 2500's can get 3200 speeds i thought

 

[DoomUK]

Quick suggestion: Is there a FSB jumper on your motherboard? If there is check what is this currently set to.

 

[bigbmxdave]

Are you putting the FSB to 200 from what it starts from? Because its safer to go up in increments of about 2/3 until you get to the desired OC.

 

[Nubius]

Because its safer to go up in increments of about 2/3 until you get to the desired OC.

bingo

Your computer isnt going to want to go straight from 166 to 200 in one bump. That doesn't leave you room to test it and get the appropriate voltage. That's a 300MHz increase right there.

I'm sure you can hit 3200+ speeds but you just gotta go in small increments, use prime95 to test for stability and add more vcore where needed

 

[PizzatheHut06]

Ok, so specifically with my XP 2500+ CPU:

11 x 166 FSB = 1.83 GHz. Should I leave the multiplier at 11 and slowly raise the FSB by 2 or 3 MHz each time, or fiddle with the multiplier as well? Also, when you say to bump it up slowly in increments of 2 or 3 MHz, how long should I leave it there? Just long enough to test for stability and voltage and then continue bumping it up? Thanks for the help guys.

 

[Nubius]

Chances are your multiplier is locked anyway so you won't even have the option to change it. Bump your FSB 4MHz the first time to 170, and then go 5MHz increment from there until you hit 200.

Each time you bump it up though, make sure of course it can actually get into windows, then run prime95 with large in place FFT's for about 5 mins...if it doesn't freeze within 5 mins, then bump up the MHz, if it does freeze or restart, then you need to up your Vcore by a couple knotches, then try the same speed again with the new Vcore and see if prime95 will then run for atleast 5 mins...once you've gotten up to 200MHz, then you need to let prime95 run for +12 hours, and continually upping the Vcore until it'll pass for that long

 

[PizzatheHut06]

then run prime95 with large in place FFT's for about 5 mins

Forgive my ignorance, but what are FFT's? Is is something in the program?

 

[Bpowa]

I have the same problem except I have an Intel Prescott 3.2 that can that can go to 3.69 but it won't load Windows... also when i try to change the ram timings to ultra it wont detect my monitor when im done, it 1gb Geil PC-3200

 

[Nubius]

Forgive my ignorance, but what are FFT's? Is is something in the program?

No, when you run prime95 you'll see what I'm talking about. Under the "Stress Test" option there are 3 choices, Small In place FFT's, Large In Place FFT's or Blend mode.

Blend mode is mainly for checking your overclocked RAM and CPU stability so with you just doing your CPU at first, large in place FFT's is all you need.