G4 using RAM only up to 1/4 of total ram

Dear all,

While I was running a memory-leaking G4 application with my workstation computer(Dual Intel Xeon 32 core (16 * 2 cores) , 128GB RAM (32GB*4) , I realized that the cpu usage(and also performance) starts to degrade from 10% of total ram consumption, and completely stops and crashes in 25%, which is 32GB of total ram. I am wondering that G4 is only utilizing one RAM socket per run, or is there a way for G4 to use the total ram installed. Many thanks for the answer.