To lower CPU multiplier or not to lower CPU mutliplier, while overclocking.

[bprogar]

I have a Conroe E6700 core 2 duo working with a Gigabyte GA-965P-S3 motherboard, and 4 gigs of Corsair dual channel TWIN2X2048-6400C4PRO (DDR2 800).

My question is this: to achieve a faster machine, is it better to lower the CPU multiplier and raise the FSB? My quarry originates from the idea that a FSB of 350 with a x10 multiplier = 3.5 ghz, while a FSB of 437 and a x8 multiplier = 3.49 ghz which is roughly the same speed. Would the higher FSB cause my machine to run faster, or would my machine run at the same speed with both settings, that is considering both worked perfectly stable? I ask because I don't know or understand the technicalities of the FSB and its effect on the computer.

Thank you,
Brendt

 

[xxxFrogg]

While I'm not an expert in this area, One drawback is that you would have to up NB and chip voltages for a faster FSB. Since most people like to minimize voltages for longer life and less heat, they usually do it the first way. I have heard there are slight performance gains(sometimes negligable) when it comes to increasing the FSB. If you plan on overclocking ram, i think the higher FSB would allow more ram overclocking potential. With the ram your using, If my thinking is correct, you would't use up all its potential until a 400 FSB with a 1:1 ratio. I could be wrong, wait for more people to chime in. There are reviews running around on both cases if you look online. They are essentially the same speed(Ghz), and the only possible performance increase would be between the FSB and Ram me thinks which is sometimes a bottleneck on systems.

 

[brencat]

Lower multi + higher FSB is more beneficial on AMD systems due to their CPUs' integrated memory controllers. On intel systems, overall core speed any way it's achieved is king, though there would be a negligible benefit you might see only in synthetic benchmarks.

 

[n7]

In theory, faster FSB is better.

If nothing else was being changed, it would be better.

But on Intel-based systems, in order to increase FSB, you generally also have to lower the RAM ratio, which consequently loosens important RAM subtimings like tRD, resulting in an overall loss in performance in most cases.

That's why you see all the AT motherboard reviews recommending sticking with as low of an FSB as possible with the higher possible RAM ratio, & tighest tRD.

That said, the difference either way is very small, too small to be noticed in real world application use, so in that sense, it doesn't matter much.