is there a way to set it specific to GSC
Possible tweaks
Check your config.ini file and see if it has settings that reflect your computer and video card's RAM properly:
CPURating=5
SystemRAM=8192
VideoRAM=4096
ObjDetail=5
TexDetail=5
Also in SCE Config util leave the Shader Level on Auto instead of DX9.
Have you tried setting max pre-rendered frames to 1?
Something that concerns me is that I changed the settings in the config.ini file as above but SystemRAM keeps getting reverted back to 2048, whereas I have 16GB RAM. Is this an issue?