The move to more graphical "Windows" meant Microsoft did tap the GPU to deliver more speed (Scotty!)
As this is released when an app like a game starts, this should never be an issue.
HOWEVER last month there was a leaky Catalyst driver that has since been corrected.
Why you ask?
Does your windows uses to much ram memory for graphic card?
Is there a solution to reduce it?

Chowhound
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GameFAQs
GameSpot
Giant Bomb
TechRepublic