question about abit nf7s and ram

[Bacardi151]

forgive me if the answer is trivial, but i rather be safe than sorry.

i have this (old) abit nf7s motherboard, and 2 corsair 512mb DDR 400mhz PC3200 and 1 elixir 512mb DDR 400mhz PC3200

in the manual it says it only supports
2 dimm ddr 400
or
3 dimm ddr 200/266/333

but would it be ok for me to put a third memory and have it run at 400 as well? or would that be bad for the mobo?

or is my only option of running 3 dimm at the max of 333.

if the case is that i can only run 2 dimm max at 400, which would be better? run 1gig at 400 or 1.5gig at 333

thanks in advance for any explanations/suggestions.

 

[furballi]

In general, the MB will default to the lowest speed RAM. If windows does not need more than 1GB of physical memory, then you will not benefit by adding 1.5GB. Run you most demanding applications and launch Task Manager and let it run in the background. At the end of the test session, check the PEAK COMMIT CHARGE. This value should not exceed the amount of physical RAM you have onboard. If PCC is over the amount of physical RAM, then you will benefit by adding 1.5GB.