graphics & memory probs

I'm using on board graphics at the moment and have noticed that when playing games my memory usage can go over 300mb starting from around 70mb. I start to have graphics problems after it goes past 250mb even though I have 512mb of memory, any idea why this is?
Anyway it's time to dump my crappy mobo and get one with an AGP slot, would a graphics card be so wasteful with memory, does this mean a card with 256mb memory is essential?

o/s: windows 2000 pro
cpu: 1g celeron (o/c to 1.12)
memory: 512mb pc133 sdram (running at 112mhz)
hdd: 40gb (ata/66)
mobo: trigem cognac

 

a graphics intensive app (anything that draws alot of 2d/3d objects) without the proper hardware supporting it will start to use ur CPU/ram as a means to continue operating. If you run too many programs and taskbar items they will eventually start to bottle neck you; its also a good idea to run adware removal tools

 

Chances are your on-board video takes alot of your RAM or doesn;t have enough allocated to it. Since you do not have AGP graphics, PCI won't be much better. If your really into gaming, invest in a better Mobo with an AGP graphics slot and a better AGP graphics card to help. Look at some past forums, everyday someone asks what video card they should get.