HELP!!! 3870x2 Settings

hello,
My system specs are a
e8400 running at 4.0
x48 gigabyte motherboard ds6
4 gigs of ocz ram running at 1100 mhz ddr2
3870x2 stock cooler.
Windows xp 64 bit.

I was wondering if anyone could tell me the best settings to run this card at with modern warfare 2. I also have a 28 inch widescreen so the resolutions are 1440X900 1680x1080 and 1920x1200 (might be off but u get the idea). Currently I seem to be a little choppy on some of the maps and would like to know if anyone could tell me the best settings to get as high as detail as possible with 60+ in the middle of all hell. Open to pretty much any suggestion... And I was also wondering about if getting another one of these would be that much of an improvement($333), or trying to liquid cool my current one(120 after more tubes etc) as I already have the system installed on the motherboard/cpu and overclocking the video Card.

I also have a problem with left 4 dead 2, at the begging of the map my fps is always 30ish if i alt tab and come back into the game it stays above 80 no matter what. Was wondering if anyone knew what this problem was or if its just the game itself(basically could this be happening on mw2). Thanks for any replies reguarding any useful information and I'm sorry if anything i've asked has already been answered but I can't seem to find anything helpful about this video card other then ppl asking about parts for it.....