How to change mem ratio with cpu in bios?

I have been trying to get my samsung ram set up right in the bios on a A7N8X MB and where do you cahnge the ratio and how do you work out what your running at from the settings.
Im running my 2700 at 125% 4-2-2-2.5
My cpu is at 154fsb my pally goes no higher. My bios is latest 1002.
Also people have said when you want to run two ram in dual mode in this asus board you have to run them in sync what does this mean exactly please. I have no option for sink apart from auto and spd also just changing the %%%.
I have thought about getting some 3200 corsair but im going to get thr 2100 B first and see what i can get as i onlmy want about 2400mhz which my samsung should do.
On the ther hand am i right in saying if i had the corsair and ran stock unless i go 200fsb on the cpu i would no be getting full bandwith out of it anyway.?
Malc.

You should be able to change the mem ratio in Advanced Chipset Features. I know the 8RDA has options all the way up to 200%(which would run your memory at 2x the speed of the FSB). Dual DDR shows a small performance gain so I wouldn't bother with two sticks.

Right now you're running the memory bus asynchronously from the FSB. (at 125%)

Synchronous means setting the memory bus to the same speed as the FSB.

If you unlock your Palomino or get a T'bred B you can set your memory to 100% and the FSB to 166. Your PC2700 memory will still be running in spec, and you can start increasing the FSB from there. See how high you can take that PC2700 and then determine if you need to get faster ram.

Thanks for the reply
Ok so when i set it at 100% it means the ram will be at 166 right? So what ever ram i have if i put 100% it will run spec?
This makes sense as when i put it 100% it puts the ram to what ever the cpu fsb is. If this is right you have opened my eyes lol.
I think im just going to put 3 256mb ddr in 2700 samsung in will 3 run better than 2 in dual mode?
Malc.

speedbird2007 said:

Thanks for the reply
Ok so when i set it at 100% it means the ram will be at 166 right? So what ever ram i have if i put 100% it will run spec?
This makes sense as when i put it 100% it puts the ram to what ever the cpu fsb is. If this is right you have opened my eyes lol.
I think im just going to put 3 256mb ddr in 2700 samsung in will 3 run better than 2 in dual mode?
Malc.

Click to expand...

The % is in relation to the FSB. For example, at 133 MHz FSB 100% Memory ratio would make the memory run at 133 MHz as well(266 DDR). Keeping it at 100% is probably your best bet. I don't think its necessary to buy three sticks; two will do, but obviously do whatever you want.

Cheers
what im going to do is just use 2 sticks and get better cooling i was going to get a volcano 7+ with the 2100+ i think ill push the boat out and get slk800 with tornado and hope the niose is not too much lol. I will be happy with 2.4g when i got all this no more.
I play flight sims that need the cpu power can't wait.
Malc.

As RnP said, the default FSB of a 2100+ is 133. So if you have the memory set to 100% it's also going to run at 133 (266 DDR). I would recommend you keep it at the 125% setting until you start overclocking the FSB. If you get that 2100+ T'bred B it should have no problem running 13 x 166, so at that point you should switch to the 100% memory bus.

Using 3 sticks on a dual-channel motherboard will actually hurt performance I believe. You want to use 2 sticks of the same size/type.

Funkz cheers does your 82mm tornado make you mad being loud?
Malc.

If I have the system out with the side panel off then yes, it's a bit unbearable.

However with Dynamat Extreme in the case and the system inside an accoustical foam lined cabinet w/ door in my computer desk, the noise is greatly diminished.

The only noise I hear comes from the intake duct around the side of my desk.

Ok Thanks funkz i better leave the side on the case ON LOL
Cheers.
Malc.