Overclocking intel core 2 quad Q8300 @ 2.5GHz on a dell XPS 630i

First question: does the Dell BIOS let you change things like the FSB freq and CPU voltage?

i can change the FBS its set at 1333.3 and i can change the voltage.

Hmm no you've got the wrong speeds there mate. You need to be able to set core frequency (the core multiplier will be set, probably at 9x). Once you get that, you can try setting it to 333MHz for a 3GHz (333MHz x 9 = 3GHz), which is more or less where you want to be to start off with. It should currently be at about 278MHz~280MHz. Anything more than 333MHz would need a stronger cooler, as then you're going to start getting a hot CPU. Decide what you want to do, and get back here...  

Nope
7.5 x 333 = 2497.5

He needs to set the FSB to 400 to get 3.0, which would probably mean a voltage increase as well.

Same cooler was used on the full range of cpu's ( upto QX9650 ), doesn't need a stronger cooler, an exhaust fan would be a help.

http://www.my630i.com/resources/overclocking.html

delluser,

i went to the link you provided how do i know if i have a locked or unlocked processor? when it says to

Go to Advanced and then Overvoltage Configuration. Add incrementally to the FSB clock for the CPU. It may require a small increase to FSB VTT of not more than one or two available increasable values in the BIOS settings. when i go there the only things i see is

CpU default voltage 1.1875V (grayed out)
CPU core 1.2000V Auto
CPU FBS 1.10V Auto
memory voltage 1.85V Auto
chipset voltage 1.25V auto

There would be an X in the processor name ( QX 9650 ) your's isn't.

Not familiar with that bios, if you followed the instructions and have no overclocking option you might want to head over to my630i.com and see if they can help you out