Using Large Address Aware Patcher With MSTS

There are various ways to set attributes in an executable file. The Large Address Aware utility is an easy way to “patch” an executable without having to resort to programmers’ utilities.

Download the Large Address Aware utility from this link. The .ZIP file is available as an attachment in the first post by its author, as “”.

The patching utility can be run from anywhere; it’s handy to keep a copy in a convenient directory.
Avoid putting it in a Program Files folder to avoid any issues with Windows UAC and special permissions.

Important — MSTS must be patched with BIN in advance to take advantage of any large memory space, even in “normal” 32-bit addressing. To derive any benefit, there needs to be 3GB or more RAM installed in the computer.

Applying the addressing patch:

1) Launch Large Address Aware.exe
2) Using the utility’s controls, browse to train.exe
3) Apply the patch
4) Edit the MEM:xxxx switch memory amount as desired, usually in increments of 1024, 512, 256, or 128.
5) Run MPROFILE.EXE which is found in the MSTS main directory
6) Test MSTS performance with your favorite routes

In operation, MSTS will only use as much memory as necessary. Opening the “window” into a larger address space simply allows more objects to be staged into RAM and possibly kept there longer before being flushed out so they can be re-used without re-loading. This can contribute to overall smoother performance. Systems with extremely fast CPUs and memory bus performance may not see the same gains, because the speed outpaces any gains from extending the memory allocation.