Alrighty vilgil, we've got a lot to cover. Firstly, you can improve FPS greatly if you drop "lightmapquality" down to 50. You should never use more than 50 because at 50, your game's shadows will look excellent. Anything over 50 is just a waste of RAM. I agree with gendestroier, you should upgrade your RAM, or buy an updated system altogether. You may be reaching the memory cap, which in turn limits you FPS a little because your RAM is having issues keeping up.
An examplento explain what I mean is like writing thank you cards. Say you can only write 60 words (or one card) per minute. Say you lose a finger (which would be the same as going from 4 GB of RA! To 2 GB) and you can only write at 50 words per minute. It now takes you a little more than one minute to write one card. So, you progress is slower. It's the same principle with RAM operations. The less RAM you have, the slower your progress, and as a result, your FPS lags.
Now, that said, your GPU is still the reason your FPS is so terrible. Your RAM plays a part in it, but your GPU is what's really holding you back.
Quote: "The issue was whether it is commonly used by all people who are playing games. In other words whether all other games also require a video to be played with a better fps. Well I suppose i can assume that although casual games don't require these cards, FPS, 3rd person shooter etc., will require a video card. Am I Right ?"
Yes! Hardcore enthusiasts like me, especially in the gaming world, drool over one part of computers more than any other part: the GPU. Every time nVidia releases a new GPU, I read every performance review, benchmark, and gameplay video with that Graphics Card to see how "she handles." The presence of a high powered GPU is THE factor that separates regular PC's from gaming PC's. The GPU handles every 3D application on your computer. If you GPU is old or underpowered, your FPS will sag as a result. Let me tell you what a GPU does
every second.
The GPU calculates all polygons, where they are located in 3D space, and which ones it can remove from the current scene because they can't be seen by the camera. It maps the textures to every in game object, and then adds specularity and other shader effects. It calculates dynamic lights' influences on the environment, and the color depth of each object. The GPU calculates Level of Detail and texture compression are extreme distances and many more other things for the renderer (these are just a few). Now, get this...if your framerate is 60 FPS, your GPU does this
60 times every second!
So, as you can see, the GPU is the most vital performance factor in 3D applications such as games. A computer needs a GPU to run games, but it needs a better one to run them well.
Whew, that was a lot...so, to conclude anticlimactically, your two options are to upgrade your RAM and GPU, or get a new custom built PC, all of which I can help you with!
My Computer Specifications: Intel i7 980x OC @ 4.2 GHz |3x GTX 580's in SLI | 12 GB, 2000 MHz RAM (Corsair) |2x 1 TB HDD | 1.2 KW PSU |ASUS Rampage III Extreme Motherboard