Graphics cards and memory
This part of the article treats all programs equally, including the 32-bit programs that run in a 64-bit environment. We'll start with a look into the graphics card’s use of dedicated and allocateable system memory. For example, 1 GB of dedicated video RAM can look plentiful at first glance, but in practice it's rarely enough. We've mentioned GMP, GART, and the fact that graphics cards can require or request additional memory. From now on, we'll use a 64-bit version of Windows 7 for testing and begin with only 4 GB of RAM installed.
The graphics card manages to assign itself an additional 1407 MB of system memory to outsource, for example, the storage of currently unused textures. A total of just 4 GB of installed RAM hardly makes sense if the game is already using 2 GB or more. The consequences of reduced assignment are late details that pop up out of the blue, lower texture resolutions, and even artifacts.
These artifacts vanish when you install another 4 GB of RAM, since this allows the graphics card to grab a fat piece of the system memory pie.
Interestingly, when installing more memory, this value does not change above 4 GB. The amount of extra available memory can be very hard to measure and quantify in numbers of frames per second, mainly because it leads to improved level loading speeds, higher detail levels, and better-quality textures. Often, the game you're playing will allow for higher graphical options, and there will be fewer artifacts when the system is heavily loaded.
Summary and Conclusion
In a 64-bit system with a powerful graphics card, 8 GB of RAM really is a must if you're going to play demanding games. This is the case regardless of whether you're using 32-bit or 64-bit applications. However, even more than 8 GB of RAM can be subjectively noticed while playing. There is no real need for 16 GB of RAM, though. Going with 8 GB is quite enough unless you're running some taxing application in the background. We’ll comment more on this subject later, because the problem is often overestimated, as shown in our 64-bit gaming benchmarks.