In attempting to overclock my cpu from 1.8 stock, I could initially only reach about 2.1ghz or a HTT of 234mHz. After this it would hang. I was using a 1.66 divider, HT at 3x, and Vcore at 1.5v(1.4 default). The only way I could get it higher was to increase the AGP from from 66 to 67. I have always heard not to touch agp/pci freq, but this allowed me to go up to nearly 2.35ghz stable and cool. Also, it this level the memory is either underclocked at 380, or overclocked around 430 depending on the divider..which is more reliable? It is middle grade ram.

Thanks for your input,

-Cont

It would help if you provided more info.

What board do you have? What chipset? S754 or S939? Is the default HT bus 800 or 1000MHz? What RAM...saying "middle grade" doen't mean anything?

I never heard of an increase in AGP speed helping an overclock.

Its a Gigabyte k8nsc board nforce3. Chip is S939 3000+, HT Bus default is 800mHz(200x4). I am not sure of the memory type, but I never clocked it above the 200 spec, so I wouldnt think that would be the issue.

Thanks
-Cont

Almost all PC3200 (DDR400) will clock to 210-215MHz without worry & many go higher. You may have to throw another 0.1v into it, but that's usually nothing to worry about either.

Here's what I'd try:

CPU freq = 250MHz
CPU multi = 9x
HT multi = 3x
divider = 1.66
AGP = 66MHz
AGP Aperture = 128MB
Spread Spectrum = disabled
CPU voltage = as necessary to stabilize

Cool'n'Quiet = disabled
fast writes = disabled

That will put your CPU at 2.25GHz with your RAM at 208.3MHz. I threw in the last 2 settings because there's been a lot of posting about it lately.

I cant get past 234 mhz HTT unless I increase the AGP freq to 67..

I tried lower memory dividers as well, and went up to 1.50V, but to no avail.
Have no clue why the AGP freq would affect the cpu clock limit.

You are actually locking the agp bus into 67mhz when you increase it to that. Without increasing it the agp bus speed rises with the fsb and you get an unstable clock. All the overclocking websites tell you to set agp to 67 to lock it before you overclock. :)

So, how does bringing the AGP to 67mHz allow me to get 300mHz higher on the cpu clock? Upping the AGP clock to 67mHz is ok to do? or will it create instabilities?

thanks
-Cont

I don't know why it help your overclocking, but there's no problem at 67MHz...the safe max is about 75MHz, but it's not recommended

I read about the C&Q being disabled also but I've been able to keep it on and use it with my OC.

As to the agp worldsphere won't be far away.

One thing to note is to be sure and give your ram its required voltage.

Tt Lanfire
MSI K8N Diamond
3000+'Venice'@294x9x3 1:1
1GB PC3200
OCZ Powerstream 520w
6600GT
WDCaviar 160gb sata x2

Indigian, did you have to increase the AGP to get past the 240ish range?

Never touched it.

Am doing 278 at the moment but everything is on stock voltages,summer heat don't mix well with oc'ing.

Tt Lanfire
MSI K8N Diamond
3000+'Venice'@294x9x3 1:1
1GB PC3200/4400
OCZ Powerstream 520w
6600GT
WDCaviar 160gb sata x2

Hmm, maybe its my mobo then that's restricting me. Highest I was able to get was 261x9x3 2:1.5 divider with 1.45 Vcore. I was hesitant to OC the memory too much since its not expensive memory. Im using stock cooling and it wouldnt go above 38 degrees.

Thanks again