who knows alot about fsb:ram ratio

chopficaro

New Member
well i know if i use a ratio to keep my fsb the same speed but increase my memory speed, my computer is supposed to be faster, but i dont have any way to estimate that speed increase, and i dont know what exactly happens in my mobo when i do that. can any particularly informed folks out there shine their light on me?
 
It doesn't matter if the ratio is not 1:1 only it's handier to have it 1:1 because it won't perform better if the RAM runs too fast or if the FSB runs too slow. It will only perform less fast if the RAM runs slower then the 1:1 speed or if the FSB runs higher then the 1:1 speed.

If your RAM is running at 800mhz then your FSB should run at 1600mhz (400mhz Bus times 4 because it's quadpumped would be 1600mhz). Or if your FSB is running at 1333 then your RAM should run at 667mhz. Your RAM needs to run half the speed of the Quadpumped Bus (otherwise known as the FSB).
 
but it is also common to run processors at an fsb of 1066 and ram at 800mhz, which comes out with a ratio of 2:3, which isnt bad at all.
 
^Guess that's because some people don't like to OC their RAMs, and of course higher FSB means better performance... oh btw, (@Timo) there's no such thing as "1600Mhz FSB" (That would be *MAD*)...the FSB runs at 400Mhz (in this example) and since it's quad-pumped, it'll perform 1600MTs (Megatransfers per second)...
 
ok so how do i rank the following in terms of overall speed? is there a formula to estimate? i dont want to buy a whole bunch of mobos and ram and bench em all.

1066fsb - 533ram - 1:1
1066fsb - 667ram - 4:5
1066fsb - 800ram - 2:3
1066fsb - 1066ram - 1:2
1333fsb - 533ram - 5:4
1333fsb - 667ram - 1:1
1333fsb - 1000ram - 2:3
1600fsb - 800ram - 1:1
1600fsb - 1066ram - 4:3
 
ok so how do i rank the following in terms of overall speed? is there a formula to estimate? i dont want to buy a whole bunch of mobos and ram and bench em all.

1066fsb - 533ram - 1:1
1066fsb - 667ram - 4:5
1066fsb - 800ram - 2:3
1066fsb - 1066ram - 1:2
1333fsb - 533ram - 5:4
1333fsb - 667ram - 1:1
1333fsb - 1000ram - 2:3
1600fsb - 800ram - 1:1
1600fsb - 1066ram - 4:3

In that order, Well, Fastest at the bottom... Slowest at the top.

Although, I'm not sure if a 1600 FSB is possible!
 
im not so sure...

1066fsb - 533ram - 1:1
1066fsb - 667ram - 4:5
1066fsb - 800ram - 2:3
1066fsb - 1066ram - 1:2-----------im not sure
1333fsb - 533ram - 5:4------------about these?
1333fsb - 667ram - 1:1
1333fsb - 1000ram - 2:3-----------and
1600fsb - 800ram - 1:1------------these?
1600fsb - 1066ram - 4:3
 
I am confused about this also, below are my system specs.What should I change to get the best performance? According to the other posts, to get a 1:1 ratio I should have 667MHz RAM? How important is it to have a 1:1 Ratio?

Asus P5N-E nForce 650i SLI Chipset FSB1333 DDR2 Mainboard

CORSAIR XMS2 DDR2 800 MHz (PC2 6400)

Intel Core 2 Quad Q9300 Yorkfield 2.5GHz (stock speed)
 
1066fsb - 533ram - 1:1
1066fsb - 667ram - 4:5
1066fsb - 800ram - 2:3
1066fsb - 1066ram - 1:2-----------That's good.
1333fsb - 533ram - 5:4------------The RAM is a little slow, but it aint bad.
1333fsb - 667ram - 1:1
1333fsb - 1000ram - 2:3-----------Would be better than the ones above.
1600fsb - 800ram - 1:1------------I'm sure would be better than the one above, I doubt you'd really see the 200MHz difference on the RAM, unless you Benched, real work, No.
1600fsb - 1066ram - 4:3

:P
 
1. RAM clock doesnt matter. If you're posting here, odds are you're not going to notice the difference (otherwise you wouldnt have posted ;)). ALl things being the same, higher clock is better performance, but the thing is, things arent always the same

2. Not only do you have to worry about ratios, but also fsb-straps... picking the wrong strap (which then dictates the available ratios) can drop your performance.
 
^Guess that's because some people don't like to OC their RAMs, and of course higher FSB means better performance... oh btw, (@Timo) there's no such thing as "1600Mhz FSB" (That would be *MAD*)...the FSB runs at 400Mhz (in this example) and since it's quad-pumped, it'll perform 1600MTs (Megatransfers per second)...

Yeah I meant Quadpumped man... I never seem to get out with the correct words..


Ké I'll just say FSB meaning the unpumped stuff. So 400FSB ;)
 
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