# memory ratio? so confused..

#### clarkboyo

##### Distinguished
O.k. what i know is that the best memory ratio to have is a 1:1, usually though you would have a 2:3 ratio. ratio= FSBRAM I have a question then:

if i have a pentium d 820 with a 14x multiplier and 200mhz fsb clock
the 820 is "quadpumped" so it has an effective of 800.

Also, I have a ddr2 5400, since its a 667 and it has a double data rate, it should be at 333.5 right?

so that means the ratio is 200:333.5 or around 2:3

Does that mean i would be able to get a 1:1 ratio if i raise the fsb from 200 to 333? And if that's true then the 333 mhz fsb makes my cpu into a 4.7 mhz cpu?( 333x14=4662) This doesn't look right, on one stick of just 667 mhz fsb?

I know something should be wrong with my calculations.. could somebody help me out cause I really want to understand how this works..

Thx much all help (p.s. sry for being dumb)

#### Jizumonkey

##### Distinguished
You pretty much have it right.

A 1:1 ratio as it's called often yields the best performance even when running the RAM at stock (as in my sig) due to the increased FSB. For you this would be 333MHz FSB which runs double data rate (DDR) of 666MHz Ram speed.

With the main FSB set at 333MHz, you will need to lower your CPU multiplier else you will not boot for sure. You need to bring it back down to something like 9x that will oc your CPU to a smidgen under 3GHz. (333*9=2997)

The down side to ram matching is the large jumps in CPU overclock, each multiplier step now increases your CPU speed by 333MHz not 200MHz, so keep an eye on that.

If you plan on raising your FSB consider disabling any chipset utilities in your BIOS to lighten the load on your chipset. You should be able to run your new settings at stock voltages and stock ram timings, infact best to do this at first and see about tweaking later.

#### clarkboyo

##### Distinguished
You pretty much have it right.

A 1:1 ratio as it's called often yields the best performance even when running the RAM at stock (as in my sig) due to the increased FSB. For you this would be 333MHz FSB which runs double data rate (DDR) of 666MHz Ram speed.

ok.. so then next question, will dual channel help out in overclocking? I've heard that if i get dual channel it has the bandwidth of twice whatever i have, (ie. 533x2=1066) but does bandwidth have much to do in oc-ing or what?