So you’re looking a getting an A4.
On board graphics can be used for gaming. Intel graphics can't compete with AMD, don’t even consider gaming with intel on board graphics.
You need to understand what you are getting:
AMD discrete (onboard) graphics can do DVD/Bluray playback, media streaming and low to mid level on line gaming as well as routine computer use just fine.
The amount of memory you have on your computer has a direct impact on your frame rates. Get the best RAM you can and a lot of it.
If you think that your A4 is going to give you 100FPS at 1080i on WOW, you are fooling yourself. You can get playable framerates at low to medium settings. That’s it.