The 4GB Memory Patcher, called the 4GB Patch, is a patch that modifies the 'Large Address Aware' flag, which, on its own, allows 32-bit programs to utilize up to 2GB of RAM (although 32-bit has a limit of 4GB). The patch changes the flag so that all 4GB of RAM may be utilized on a 64-bit system. On 32-bit systems the 4GB patch does not work, but the 3GB switch can be used instead, more informations can be found on the Wiki page (3 GB Barrier ). RAM does not allow one to play MIDIs faster, rather, it allows you to load MIDIs. Because MIDIs are loaded into the RAM before being played, some MIDIs are too large to fit in the RAM, and thus, the program crashes. 

Note that how many notes you can load will also be dependent on the processor speed of your computer. A faster processor will allow for more notes to be loaded.

On 64 Bit Programs 4 GB Patch is no longer needed and Note count limit is decided by Computer's RAM unless the program is limited