What RAM do you have?
Different RAM obviously has different timings.
You can try lowering the actual timings on the RAM by dropping by MHZ its running at...
For example... My RAM in this PC here, is DDR400 Samsung.
At stock, its good for
3.0-3-3-8 @ 200FSB
2.5-3-3-7 @ 166FSB
So, in theory, lets say I dropped the RAM to run at 133, then I might be able to go to
2.0-3-3-6 @ 133
Not always the case, but worth a shot.
This RAM is also useless at running at 1T so its unfortunately 2T... 1T will be quicker, however, its 4GB, and at this time, I am hoping that 4GB will be quicker than 2GB but so far, its only proved to be a waste of time really. In fact, its no better really than 1GB - the only help it has been in running multiple Virtual Machines, other than that, for me, 4GB has proved no better than 1GB.
Now, I also know that the Corsair 4400 RAM, was perfectly happy all the way up to about 290FSB on stock volts, but, at 3.0-4-4-7 ( I think? ) however at the 1T I mentioned earlier.
Why 1T over 2T?
Well, if you didnt know, this is the time it takes for the memory controler to access the RAM. 1T is how long it takes to do it... 2T being obviously longer and therefore slower, so 1T is quicker than 2T.
I have found, that altering the timings on the RAM is quite often a completely futile task... Requiring a lot of effort to get things stable, and yet the results while sometimes can be rewarding, are quite often abysmal. At the end of the day you will be looking at something ridiculous like about 1% or 2% so to be honest, unless you are going to go silly, so, I wouldnt bother really.
I no longer do... on all my systems, I have just opted to get better / faster RAM in the first place and have done with it.