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View Full Version : FSB to RAM Frequency

Murp
08-08-07, 02:43 PM
Hey guys I've searched high and low and I don't seem to be getting it.

First off I have a Pentium 4 630, Corsair TWIN2X1024-5400C4 (which is 2x512MB PC2-5400 DDR @ 675MHz), and an Asus P5ND2-SLI Deluxe motherboard.

I am running that Corsair memory in a dual-channel configuration. By running in dual-channel does that double the frequency to 1350MHz (meaning I need a 1350MHz FSB to take advantage of all that speed)? Common sense tells me no, but what then does my FSB need to be to take advantage of that RAM in a dual-channel config? By default, my processor's FSB would be 800MHz but it's running at 900MHz right now.

What should I adjust my RAM frequency to be to make sure that nothing is slowing down the system?
JamesXP
08-08-07, 02:51 PM
Well if the P4 is at 900MHz it means your first FSB is 225 so if your ram can run 450 which it can it can do 1:1 but if you get the fsb to 333 the ram can run 1:1
Murp
08-08-07, 04:13 PM
So you're saying long as my RAM is half the speed of my FSB that's the best?

@ 900MHZ, RAM should be 450MHz
@ 1000MHZ, RAM should be 500MHz?
etc?

That's kinda what I thought. Thanks for the confirmation. :D
smokie mcpott
08-08-07, 04:40 PM
dual channel has nothing to do with the frequency
dqtus
08-10-07, 02:29 AM
Just to jump in here, isnt it better for Intels to run in async mode so it's better to boost the ram speed? Anyone want to answer that question. I'm a bit torn on sync or async with intels. Can anyone show any performance difference?
ancalime
08-10-07, 03:08 PM
Just to jump in here, isnt it better for Intels to run in async mode so it's better to boost the ram speed? Anyone want to answer that question. I'm a bit torn on sync or async with intels. Can anyone show any performance difference?
The difference in real time performance is miniscule, almost negligible. Running 1:1 is just the most efficient way to go but I imagine running a 5:6 ratio to boost your RAM frequencies may help in some benches.
Reefa_Madness
08-11-07, 09:03 AM
Using the dividers will allow you to run the ram to its fullest potential. Is it a huge difference...no, is it an improvement in system performance...yes.

Does it cost you more to run your ram faster...no.

If it peforms better and doesn't cost you anything, then why would you not want to do it? After all...that is precisely the reason the motherboards have memory dividers...to utilize the ram to its fullest. It also allows you to tweak to find the best overall cpu speed by varying the cpu multiplier and using the memory dividers.

Seems rather simply to me...but for a confirmation, see what's listed as #2 in this analysis.

http://www.ocforums.com/showthread.php?t=521047