Do you mean you need dedicated GPU for your slim tower to play FSX?
Also list your specification.
Lenovo m58p. Extremely small. about the size of the new xbox slim.
Intel Pentium III xeon @ 3.00 GHz
upgraded RAM 4GB
sad 280 watt power supply
sad 140 GB hard drive(thinking of getting external one)
Win7 32 bit pro
Currently running integrated Q45/Q43 graphics.
With low graphics, high end add- on plane, and Fraps...I can get around 15-20 FPS with gamebooster running. I got as low as 2 fps once.
Sometimes my computer goes on steroids and runs at 50 fps with slightly blurry graphics.