Good Day,
I can overclock Athlon XP 2400 either of 2 ways.

1) 160/32 mhz *@ 13 = 2080 mhz, or
2) 149/37 mhz @ 14 = 2086.

The first number is FSB (160) and the second number (32 for 132 mhz) is for pci bus and agp bus.

Both method 1 and method 2 yield similar cpu speeds. But agp bus is at 132 (method 1) versus 137 shown in method 2. The agp is overclocked by 4 mhz in method 2 versus underclocked 1 mhz in method 1.

Question: Does method 2 yield better in game graphics performance because of +4 mhz overclock in spite of lower FSB? Or, does method 1 yield better gaming graphics performance in spite of -1 mhz underclocked agp bus because of higher FSB? In other words, does the additional 4 mhz on agp bus offset the lower FSB setting or does the higher FSB offset the lower agp bus speed and yield the better graphics performance?

Respectfully,
Jasper

the higher FSB is the way to go on your overclock, i'm pretty sure the agp bus running a little slower won't hurt as much as the FSB helps.

you can test out both your methods, download fraps it displays your fps constantly.

Thankyou for your reply. I will fetch FRAPS shortly. May be I will try benchmarking using 3dMark also.
Jasper

having the higher fsb w/lower multiplier,compared to higher multi/lower fsb ,will always yield better performance.

The extra memory bandwidth is essential. Like everyone said, go for the highest FSB you can get

True! When I am F@H, the proteins fold 2-3 hours faster @ 166*9 than 133*11.5 even though 166* 9 is slower than 133*11.5 MHz wise. Always go for as high a FSB as you can. I recommend going for 166FSB as all Athlon XP's can do it just fine, it's only basically ram and motherboard limited. You should be okay if you have a 1/5 divider. I heard some Athon XP's are fine @ 200FSB if you have a 1/6 divider.

mine is set for 10x183, fold runs quicker, and I get PC2700 or slightly better bandwidth with my PC2100 DDR (According to Sisoftware Sandra 2003 professional) Plus I have a nforce2 board, so my AGP (Is adjustable, stays locked at 66) and PCI are always at the normal speeds.

ok how do you get a devide, waht is it and how do you get it to work, beaucse i wanna try useing one, please send me a link or something to know wht to do

Well, first, it helps to post what kinda motherboard you have, and wether or not the BIOS has a PCI/AGP divider in it.. If thats what you're talking about

That's what he is talking about.

Wow...this forum rocks...I never thought to get so many responses so quickly...Thanks.
Now, I'm wit the other man...what is a divider? I've got Asus A7V333 motherboard.
Jasper

Sorry dude, you are confused some where.

Your stock clocks should be:

133 / 66 / 33 ( fsb / agp / pci )

You can see that the ratio of those number is 4:2:1 . This is what is called a 4:2:1 divider.

As you over clock to a FSB of 160 you can see that the old 4:2:1 divider would run your pci and agp way out of spec:

160 / 80/ 40

You agp and pci devices would likely not tolerate this! By switching to a 5:2:1 divider you get:

160 / 64 / 32

Which brings your agp and pci bus back into spec.

Your mobo may or may not also have a 6:2:1 divider.

Anyhow, the dividers are just bios settings. You have to go look for them.

My point was that your agp and pci bus is definately not at "132" or "137".

There is something here you are misunderstanding ....... I am just not sure what it is!

I just figured out where you are getting confused.

When you overclock to FSB 149 with a 4:2:1 divider, you get:

149 / 74 / 37 Not 137! You agp is 74 and your pci is 37.

When you over clock to 160 your board must auto detect that your are running your shiznit out of spec, and switches you to a 5:2:1 divider automatically. This gives you:

160 / 64 / 32 Again 32, not 132.

Is that making sense to any one else?

Hello,
I see your point. I made an error saying 137 was my pci bus speed...absolutely WRONG...thanks (and I call myself an "overclocker, Hah!).
Your comment "Your mobo may or may not also have a 6:2:1 divider." would yield bus speeds of

198 / 66 / 33

right? I think I got it. You would probably need water cooling or LOX to cool at this speed, huh? How many mhz can one increase with a heatsink and fan (at what point should one consider liquid cooling)?
My mobo has system bus (FSB) and pci bus choices presented in the bios in this fashion:

133 / 33
134 / 33 ...
150 / 34
151 / 35
152 / 36

and so on up to

200 / 37.

Is it correct to assume that agp bus is ALWAYS twice the pci bus? Are they linked in this fashion, 2:1?

What is the maximum pci bus you recommend? What is max FSB you recommend for Athlon XP 2400? What about voltage? My minimum clock speed is 13. Recommend a site with these settings, please.

I am running 158 / 32 because 160 / 32 crashed to blue screen after 20 minutes of gameplay so I backed off a few points...is this where I begin boosting (raising) my voltage from default to get higher FSB? (It won't even boot above 163 FSB.)

158 / 32 runs great...temp at idle is 52 degrees C and during gameplay raises to about 63 degrees C at room temperature of about 80 dgrees F ( I read somewhere that Athlon XP's max operating temp is around 90 degrees C.).

I realize this is a long post so feel free to just jump in and answer what hits your fancy and I will "google search" the rest.
Thankyou for your input and this informative edumacation, huh, eduation.

Jasper

Thanks putwig, you got it right. Im so used to my nforce2 asus board, automatically locks the PCI speeds. And has AGP speed adjustable too..

Quote: Originally posted by Jazzyjazz Your comment "Your mobo may or may not also have a 6:2:1 divider." would yield bus speeds of 198 / 66 / 33 right? I think I got it.

That is correct. Divider options aren't really there to help us overclock (although they surely do that!), they are present to allow that mobo to support a variety of processors:

3:2:1 (100 / 66 / 33) for old athlon T-birds and durons

4:2:1 (133 / 66 / 33) for the later T-birds and palominos and early thoroughbreds

5:2:1 (166 / 66 /33) for the later thoroughbreds and early bartons

6:2:1 (200 / 66 / 33) would support (in theory) the newer 200 MHz fsb Bartons (check mobo sites for actual compatability!)

Quote: Originally posted by Jazzyjazz How many mhz can one increase with a heatsink and fan

This question is impossible to answer, there are far too many variables (including dumb luck!) to even attempt a guess at oc success. You oc until you are unstable or hot. I usually find the maximum stable oc and then back down a tad.

Quote: Originally posted by Jazzyjazz (at what point should one consider liquid cooling)?

Another impossible question! Liquid cooling is a big jump.

You decide to water cool when the benefits ( efficient, quiet, better oc, pimp as all hell, dying to try it) outweigh the negatives (high maintenance, expensive, takes up space, risk of leaks).

Only you can answer those questions!

Quote: Originally posted by Jazzyjazz Is it correct to assume that agp bus is ALWAYS twice the pci bus? Are they linked in this fashion, 2:1?

For all intents and purposes, yes.

Quote: Originally posted by Jazzyjazz What is the maximum pci bus you recommend? What is max FSB you recommend for Athlon XP 2400?

Again, whatever will run stable, and within comfortable temperatures.

Quote: Originally posted by Jazzyjazz My minimum clock speed is 13. Recommend a site with these settings, please.

You need to unlock the lower multipliers. Do a google search for the that, I have not unlocked anything since an old athlon T-Bird!

Quote: Originally posted by Jazzyjazz I am running 158 / 32 because 160 / 32 crashed to blue screen after 20 minutes of gameplay so I backed off a few points...is this where I begin boosting (raising) my voltage from default to get higher FSB? (It won't even boot above 163 FSB.)

Increasing core voltage and ram voltage can definately buy you some stability, but, it will also generate more heat ...... and could substantially decrease component lifetime.

Quote: Originally posted by Jazzyjazz temp at idle is 52 degrees C and during gameplay raises to about 63 degrees C at room temperature of about 80 dgrees F ( I read somewhere that Athlon XP's max operating temp is around 90 degrees C.).

You are already outside of my temperature happy place. I would not push it any further without better cooling.

Quote: Originally posted by Jazzyjazz and I call myself an "overclocker, Hah!).

You use the term rather loosely.

i love bein able to lock my pci/agp busses

Thank you Putwig, and to all others who took time to read/respond to my post...my questions are answered.

Have a GOOD day.

Jasper

You are welcome!