Q6600 6GB RAM What's better for MineCraft 1GB GDDR3 or 1GB GDDR5?

1gb gddr5

1GB of GDDR5 is better than 2GB of GDDR3

For vram on a graphics card, GDDR5 is much, MUCH faster than the old GDDR3 memory used on old ATI graphics cards.

GDDR5 is better.

GDDR5 is the better type of RAM. It is faster. That being said, GDDR3 will work fine for Minecraft. It is not very demanding.