Chess Gator wrote:Hi,
I notice motherboards that can hold up to 128 gigs of RAM. If a fast CPU was being used how much RAM could a commercial chess software program like Shredder 11 use?
thank you

This is only a theoretical value. You will only find such amounts of memory on very large server farms or on supercomputers.
In reallity all desktop Mobo's have only up to 4 DDR slots. So you can get 8Gb Max. (2GBX4).
You need to have a 64-bit OS to take advantage of more than 4 GB. with a 32-bit OS you can only use up to 4 GB but even then it will only use 3.5.
In the server area you have more DRAM slots, so you can usually get 16GB.
If you want more than that you will need a VERY expensive server platform, such as as a Blade.
But as a casual Desktop user you will only need about 4GB with an 64-bit OS and that should be enough.