TechPowerUp posted a review on the MSI GTX 780 Gaming 6 GB
A quote from the article:
MSI's new GTX 780 Gaming 6 GB doubles the available video RAM over the reference design, which has just 3 GB. With latest titles requiring 3 GB VRAM minimum for Ultra textures, this 6 GB card could help provide a performance advantage. We will investigate this claim using our brand-new VGA test suite.MSI GTX 780 Gaming 6 GB @ techPowerUp