A quote from a post by Zec Murphy.
"If you are seeing the draw distance limiter come into effect, then this means you are reaching the resource limits for Trainz. Remember, Trainz is a 32bit application, and hence does still have a limit on the amount of RAM it can use - a 64bit OS will improve this, but it's still limited to about 3GB IIRC (1GB on a 32bit OS from memory)".
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So I would guess your 8g is more than enough with plenty to spare. :wave: