Memory usage less than 2GB even w/4GB Patch

[pickler]

Hello all. i recently installed Living SH3 mod. what a mod! i also added my own additional mods like sh4 effects, etc...all in all the game is very resource heavy but my machine is strong enough to handle i think:
intel core 2 quad 3.0Ghz
8gb RAM (4-4-4-12) latency
AMD Radeon HD 6850 OC to 800Mhz
Windows 7 Professional 64-bit

anyway, i have been monitoring the game with performance monitor and i have noticed that it does not use much CPU/RAM. Max RAM usage that i have seen was 1.7GB and CPU usage is almost idle with exception of first core working upto 70%. i'm not sure why there is so much stress on first and none on rest. For my other games all cores work on similar levels. The game still lags when close to large convoys or base at 256x compression or above. At 1024x nearly comes to less than 1fps near convoys or base. However it can do 4000x easily at sea with no traffic with good fps. i was wondering why my sh3 doesn't use more ram and cpu to improve performance? My video card is overkill for this game so that can't be the problem as i the fan is quiet meaning its not working hard. i was also wondering if anyone knew how to make my SH3 run without steam as steam uses lots of ram and cpu? thanks.