Overclocking question about lowering clock ratio

[RedTiger]

I can't find the answer this to this anywhere. My question is simple: is their any benefit to lowering the clock ratio on the CPU and raising the frequency, or should you always leave it at the default -- which is the highest value possible?

 

Example: I have an E6850. The default clock ratio is x9. If I want to overclock to 3.2 ghz, which is better, 400 x 8 or 356 x 9?

 

I realize there may be other reasons to eventually lower the clock ratio, but I'm not sure if there's any benefit in a case like I described.

Edited August 16, 2009 by RedTiger

[EtherealN]

The benefit could be in memory handling, in that there are more chances for the FSB to feed and extract data to and from the CPU if the ratio is lower. That's a purely theoretical benefit though and I don't think it's big enough to matter. In my (limited) experience, most FSB's will start to choke well before the Exxxx chips do, and it's also the FSB clock that governs the RAM clock through the ratio. So while there might be miniscule gains in some scenarios to have a lower multiplier and higher FSB, in my opinion the drawbacks outweigh those gains.

 

A lot easier to stay in control of the system when doing it in a way that has minimal impact on FSB, since that thing touches on so many things.

[Kuky]

From what I've read over the years when I wanted to overclock my system, I read that best CPU:RAM speed ratio (or FSB) is 1:1 (for compatibility and stability) so if you have RAM that is reated higher then what CPU is rated and you have good motherboard that can do higher FSB I think it is batter to lower multiplier on the CPU and run higher FSB to achieve 1:1 ratio on CPU:RAM. Other then that I don't think there is any other benefit.

 

I personally stuck with highest multi (default) for the CPU thinking very high FSB does stress the motherboard more.

[RedTiger]

Thanks guys! As you mention about RAM, one side effect is that the RAM is running at a funky time, 712 mhz, which is under its default raiting of 800 mhz. I know from personal experience confirmed with online discussion that my board doesn't like RAM to be OCed over the default speed, so there's no point in going over that amount. I'm wondering if an extra 44 mhz on the FSB would be worth it to have the RAM at the default and faster 800 mhz. If I'm reading correctly, you all, generally speaking, don't think so.

Edited August 16, 2009 by RedTiger

[Ramstein]

I went into my bios on my Asrock 4coredual motherboard and changed the memory timing from Auto to manual and my FPS in Black Shark was around 10 to 20. Now it's 15 to 40 fps..

:music_whistling:

[RedTiger]

I went into my bios on my Asrock 4coredual motherboard and changed the memory timing from Auto to manual and my FPS in Black Shark was around 10 to 20. Now it's 15 to 40 fps..

:music_whistling:

 

*ALL* you did was flip the switch to manual? You didn't fiddle with the actual timing settings? :huh: Are you pulling my leg? :D