Raspberry Pi Model B Rev 2 has 512MB RAM that is partitioned between the CPU and the GPU. If the Pi is working as a headless server or the Pi desktop is being accessed via VNC (which doesn't utilize the GPU) the memory split between the two processors can be altered to assign more memory to the CPU for running applications.
Default GPU memory on Raspbian is set to 64MB and the minimum recommended to ensure proper operation is 16MB (Pi Camera Module requires a minimum of 128MB RAM). To modify GPU memory to 16MB either:
- edit /boot/config.txt and set gpu_mem=16; or
- run sudo raspi-config and select 8 Advanced Options -> A3 Memory Split and modify 64 to 16
Save the change, reboot the Pi, and enjoy the CPU memory boost!