Absolutely baffled by memory settings on IC7

Ok, can someone kindly explain the difference between i845 and i875 in the way they overclock memory and CPU?
With my old board I increased the CPU FSB and the memory bus increased accordinglyfrom 266 DDR MHz or 333 DDR MHz to whatever.
Now with this IC7 I'm seeing nothing which resembles this, rather it's giving me 133/66/33 and when I overclock the CPU from 133 to 150 I'm not overly clear on exactly what that's done to the memory...

Can someone give me a step by step guide as to what it all means and how to go about overclocking the memory bus/fsb etc?

With default settings, the memory ratio is set automatically. Right below the CPU settings in the SoftMenu section of the BIOS, set the N/B Strap to 800 or 533 or whatever depending on which CPU you have. That will unlock the grayed out ratios on the next line. Of course, the 1:1 ratio keeps the FSB and memory bus the same. For example, the 5:4 ratio allows the RAM to run slower than the FSB and 4:5 ratio allows the RAM to run faster than FSB. What CPU and what RAM do you have, maybe I can suggest a good setting to help you get started.

Cheers.
I have a P4 2.4b which is fine at 2.7, and 3200 XMS Corsair 2x512 RAM.

Ok, cool! At 150 FSB (2.7 gig), set the N/B Strap to 533 and see if that gives you the 3:4 ratio option. Set the RAM to 3:4 which should put your RAM at DDR400 (right smack dab in spec).

batboy said:

Ok, cool! At 150 FSB (2.7 gig), set the N/B Strap to 533 and see if that gives you the 3:4 ratio option. Set the RAM to 3:4 which should put your RAM at DDR400 (right smack dab in spec).

Click to expand...

Ok, cheers, shall try that.

EDIT: There's no 3:4 option with the strap at 533, just 4:5. Best I can do with the CPU @ 2.7 is 374 DDR. I have to overclock the CPU further to get any success.
I remain slightly bemused...

I think you have to use the 400 boot strap for the 3:4 ratios. At least on the IS7 which has a similar bios to the IC7.

Yes, I think you're right. Try the N/B strap 400 setting and see if that gives you the 3:4 ratio option.

Wouldn't dropping the strap down to 400 from 533 actually reduce overall system performance?

-Tyrinon

No, all that does is to change the memory ratio options to what would normally be expected for that CPU. It does nothing to change performance.