32-bit Windows games are limited to 2048MB of main memory and 512MB video memory. 64-bit Windows is capable of recognizing up to 18EB of address space.
“Data of Interest Does not Fit in Main Memory” was heard back when mainframe computers were in widespread use. Today even the mainframe is now using a 64-bit architecture primarily to support vast amounts of peripheral workloads.
Most gaming rigs have 4 memory slots, we strongly suggest using 4 identical sticks for best results. Some Intel motherboards may have 6 or more memory slots, they also should all be identical for best results.
Beware that the Xbox One and PS4 come with 8192MB of memory. The consoles are using a 64-bit OS too — so it’s 64-bit looking forward. Remember that the AMD64/EM64T is fully backwards compatible with 32-bit games. The CPU can run a blend of 32-bit and 64-bit without problems.
Anybody play Halo 2 for Windows Vista? This means that existing collections can be played along with newer generation 64-bit games. We have a large library of legacy games and we often play some titles that are over 10 years old. With the updated engine, Quake II is still a great game and it runs fine, even on Windows 8.1 x64. No console can deliver the backwards compatibility the PC provides.
DDR3 is now readily available in 4096MB and 8192MB sizes. DDR4 is increasingly available in 4096MB and 8192MB sticks. DDR4 should surpass DDR3 in 2017-18
16384MB DDR4-2400 sticks are now at the high-end of the range for AM4, X99 and Z170 setups. Larger 32768MB and 65536MB DDR4 DIMMs can be expected in about 5 years. 128GB server memory will eventually find its way to gaming rigs once the server market dries up.
MAX MEMORY FOR X64 VERSION
|WINDOWS VERSION||MAX RAM|
|Windows XP Professional and above||128GB|
|Windows 7 Professional and above||192GB|
|Windows 8.1 Professional and above||512GB|
|Windows 10 Professional and above||2TB|
The AMD64 architecture which is used by both AMD and Intel only have 48 address pins which limits memory to 256TB. This will likely be changed soon now that extreme servers like the ones Facebook use depend entirely on RAM for their operation.
We expect that more address pins will be used as file systems exceed 256TB for memory mapped addressing purposes. The most extreme servers have upwards of 4TB of memory. In a decade or two, servers could well exceed 32TB of memory.