the multiplier and its effect on CPU performance, please explan...

[OsageCowboy]

so, what exactly does the multiplier do for the CPU's performance? I am presently wanting to do a minor O/C job with an E6400 and DDR2 rated at 800 mHz.

it seems as though raising the FSB to 400 mHz and adjusting the multiplier DOWNWARD to 6 or 7 would have me running at around the mHz range where I'd like to hit (i.e. 2.6 gHz or so), and doing this would preserve my RAM at its rated 800 mHz. doing the traditional incremental adjustment to the FSB from 333 mHz and upward seems like it would cuff my RAM below its rated 800 mHz, and so that may or may not be beneficial.

basically, would a performance hit from adjusting the multiplier downward be more substantial than having RAM operate at less than 800 mHz? please advise.

 

[BillParrish]

I had a bit of trouble following that but you have the right idea. If for some reason (heat, stock heatsink) you could not run the cpu at its highest multiplier, lets say its mulit is default of 8, becasue at 8 x 400 = 3.2 GHz cpu speed generates too much heat or your are just not comfortable with that high of an overclock, AND your memory is pc6400 (800MHZ memory) you could lower the mulitplier to 7 or 6 and still run the memory at its rated 800MHz (DDR2 speed = FSB x 2 ) but the cpu would run at a more conservative 2.8 or 2.4 GHz. This allows you to run the cpu at a speed more to your liking and still get rated performace (memory bandwidth = speed to transfer data to from cpu) from the setup.

I didnt cover part of your question because I am not sure I got it right but I think the above was what you where mainly asking, anyway hope it helps a little bit.

basically, would a performance hit from adjusting the multiplier downward be more substantial than having RAM operate at less than 800 mHz? please advise.

hmm , probally yes. but a lot depends on the program(s) and how memory intensive they are. I am having to speculate here, and you could run benchmark programs or better yet the actual applications and time some operation, I would rather have a core2duo running at 3.2 Ghz and memory at 667 than have the cpu running 2.4 and the memory at 800. Most of the real work is done by the cpu. that is a generalization but probally fair.