I'm using a single laptop for 5man boxing: Dell Vostro [Core2Duo 2.0GHZ + 4GB ram + Ge Force 8600(256MB)]
OS: Windows XP [Not a Vista fan]

Using Keyclone Maximizer:

Old Setup: Main Window at the top while 4 windows at the bottom. Text is slightly unreadable but manageable for the 4 small windows but I have no problems in multi boxing in Outland instances.

New Setup: Main Window in my laptop screen while 4 windows tiled in my 32" HDTV as my Extension Monitor. Finally another use of my TV. It's like 4 full screen version of my laptop


Normal FPS

Main Window:
- 50+fps [Normal instance flow like ramps, I tank and 4 lvl 60 DPS kills it]
- 15-30fps [when my lvl 80 Pally pull all the mobs in SM Cath (I bubble, open the cathedral door, hit the boss, then drag all the mobs back near the entrance where my low level are located]

In Dalaran or in Org it drops to 20-30fps

4 Windows: 10-15FPS while I'm on my main window


Temperature
Vostro by nature is really hot but good thing I'm in the Bay area so I'm fortunate enough to have this kind of weather and a my laptop cooler is just an icing on the cake.


Addons Running: Questhelper, Tourguide, Cartographer, Lightheaded, Omen, Recount, ScrollingCombatText, Auctioneer...etc

- My rule in gaming is always to stay away from internal video Chipset because its only built for word processing and browsing.
- You can't blame everything on your laptop because your realm might be the caused of your low FPS. Try new servers and see if you'll have the same problem.