Multi Monitor FPS question...

I have stated in another thread that I am buidling a new rig for my quad-boxing team. I currently use a Dell Vostro 1700 laptop with an 8600GT card and 3GB Ram. It works perfectly fine except that I am running 3 clients on a 4x4 window each and 1 client on the rest of the screen. As soon as I hook up a second monitor and move my 3 alts over my FPS goes way way down. My plan for my new rig is to run my main on a 17" wide screen I have and my 3 alts on a 20-22" I plan on getting. I am however worried that the 8800GT I put in this rig will be bogged down by the dual monitors, so I'm really thinking of getting another 8800GT for the second monitor. Any thoughts or experience?

There are a lot of threads on this subject floating around. Since I'm such a swell guy, I'll sum up what I've learned (both from reading those and trying it myself) :):

muti-monitor support in XP, from a performance standpoint, sucks. The most useful mode, dual-view, has a performance hit. If you run span, you have to have the same res monitors, which most often is probably not the case. Having more than one video card doesn't help, it's a problem with the windows rendering model.

multi-monitor support in Vista is better, and is supposed to fix this probelm. Whether it does or not is not entirely clear to me, but I'd say generally speaking it's better. However, overall vista comes with its own share of issues, that may offset any gains made by this improvement - or worse.

I'd suggest doing some searches for this info (it's spread about a lot different threads) and draw your own conclusions. That's just what I've surmised.