I'm afraid there is still quite a bit of conflicting and outdated information out there about this game.
TS3 is a 32-bit application only. It cannot possibly use/address more than 4 GB of RAM, actually the absolute upper limit is really 3.7 GB due to some overhead.There are no ini or sgr settings that can change that, the one that is still commonly referred to in that manner does nothing for actual RAM usage and its default value is 20 GB anyway (commonly misread as 2 GB and this is a measure of the theoretical upper limit to the script heap, not RAM usage). I also would not recommend changing DEP settings, EA fixed that issue with one of the patches somewhere in the 1.50s I think it was.
If your system has plenty of RAM to use, and it certainly sounds like yours does, the goal becomes keeping the game's usage under the danger zone that begins around 3.2-3.3 GB or so (this will vary slightly by player and system), not finding ways to get it to use more as those will never be successful. According to the Task Manager, how much RAM is the game actually using, in MBs or GBs not %s, once it's started up with the game clock moving forward smoothly, and again after say a half hour to an hour of gameplay if you are able to keep it running that long? Which world(s) are you playing and do you see a big difference if you startup a new test game in one of the gentler to play worlds such as Sunset Valley, Riverview, or Twinbrook?
