P4P800 Dual Channel Memory Speed

First off - I'm a noob of the 1st order. And I can tell it's going to
take quite some time to get this all down.

Now.. my question --

When I use only one of my Infineon 512 DDR 400 simms, at post
it states memory @ 400. When I use both, it states dual
channel at 320. Is this normal? Also, any suggestions to get the best out of what I've got here?

Last -- where is the best place to start on all the technical aspects of overclocking? Thanks.

perhaps your two memory chips aren't the same

it looks like the board automatically set a 5:4 ratio for the chips, because the spd rating for one of them is pc2700

btw, welcome to the forums

Makes sense... but I had two different ""DDR400"" 512's in it before I went and bought these two. If I put either of the 2 in by themselves, it shows 400... but together 320. I'm sure it's something simple but while researching this on the net, I can't come up with an answer. And I've learned to always search before asking a question already answered. CPU-Z shows the exact same info for DIMM 1 & 2.

If I wanted to force the system to treat both as 3200 by not using the SPD, what do I need to set to what? Tkx.