i want to know what does the graphics memory have to do with the graphic card performance,does a 4 gb graphic card better than 2 gb graphic card??,if 2gb graphic card has a higher clock speed.?
how much clock speed is needed for better gaming and how much memory
You can't just say a card with more memory is better than one with less. The same with clock speed. You can only directly compare 2 cards of the same manufacturer and generation. So you can compare 2 cards of the GTX 5xx series or 2 cards of the HD 7xxx series but you can't compare a GTX 5xx card to a HD 7xxx card based on memory and clock speed. They use different architectures so you would be comparing apples to oranges.
think of graphics memory as stored images when gaming. its used less for the quality of the image, but more for how many images it remembers at a time. for instance, computers with multiple screens need the extra vram, since the gpu has to compute 2 screens at once. another example is how far you can see. some games have the ability to limit the range of vision you have against certain objects. vram helps alleviate that problem. this is more apparent in shooters and rpgs, as there is a limit on how far the gpu can store images from distances.