what intel cpu's integrated graphic chip is doing?

[ekBenchmark]

I'm using a computer with intel i7 620m cpu and nvs3100 graphical card.
the cpu has integrated graphic in it. so what it is doing when the nvs3100 is diong graphic tasks in actual use? some say some computer can switch between dedicated graphic card and the cpu's integraged graphic. is that so?

does the integrated graphic unit doing something when play HD video or some other heavy graphical tasks?

did the integrated graphic contributed some scores in the performance test's cpu score?

intel i7 620's top power consumption is 35W, so is it far less than 35W if we have a dedicated graphic cart?

[David (PassMark)]

Yes the i7 620m in a package with 2 chips. The CPU and a GPU. But the included GPU (integrated graphics) is rather weak.

The integrated graphics will do nothing to add to the CPU benchmark scores.

As you also have the NVS3100 chip set, you'll probably find that the integrated graphics isn't actually connected to a physical port on the machine and you don't have the drivers loaded for the integrated graphic. So it will be doing nothing for you.

[ekBenchmark]

thank you, what about power consumption? does the top power consumption has been lowered because the graphic core is not working? i did not found any idea about this from intel's site.

[David (PassMark)]

Less power would be used by the idle GPU. How much less I don't know. You would need to take some measurements.