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Have I understood the basics of overclocking the 865 chipset?

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Mar 9, 2002
The belly of the beast (Wales)
I'm new to P4 overclocking and I want to make sure I've understood what I'm attempting to do, before I order some components. I'm looking at a 2.8C & Asus P4P800-E Deluxe.
Are my following deductions of overclocking the 865 chipset correct?

1. FSB can be set between 100 to 250+, often in 1 MHz increments up to 200 MHz and then often in slightly larger increments.

2. AGP and PCI busses can be locked at 66/33 or higher if required. i.e. they are completely independent of FSB or memory speed.

3. The thing I'm definitely not clear about is how the Memory settings work! When I set the memory clock, is it an absolute value or is it a ratio of the FSB?
i.e. in the Asus BIOS you can choose between 266 and 533 or Auto. So if my FSB is 250 and I set my RAM to 400 will the RAM setting be 400 or 250/200 * 400 = 500?

I know synchronous RAM is best for performance, but I'm not yet sure if it's worth me paying the premium for PC4000 over PC3200!
I don't want to spend the extra on PC4000 and find that I can't run the CPU and RAM synchronously at high FSB settings. i.e. The CPU can't handle a FSB of 250, so I'm forced to use say 240 FSB and the RAM then will then either be set to PC3200 (asynchronous) or PC3840 (synchronous). Help!


Smiling Crow


Feb 1, 2004
Dacula, GA
smilingcrow, Here are some answers to your questions

#1 - your are correct
#2- You are correct again . In order to overclock you must be able to lock down the PCI/AGP bus to 66/33 or a value that is close. (my MSI board will only allow me to go to 67/34 inless I enable SATA)
#3 - this is how you set the memory dividers on my board but I am not sure of others

I hope this helps