As the NVIDIA helpdesk described
In Windows XP, NVIDIA graphics card driver controls how system memory is allocated to the GPU. But with Windows Vista and Win7 it now controls the allocation of system memory to the GPU for TurboCache functions. The Display Properties pages show the shared system memory (SSM), or how much memory is allocated for NVIDIA GPUs to use for TurboCache.
The Shared System Memory in Windows NT 6.0+ actually performs like the Turbocache or HyperMermory in Windows XP but with different management layer.But interestingly,maybe most of the nowadays UE4 developers have much larger VRAM GPU(2GB+),they didn’t actually ran a test on an 512MB VRAM GPU,when I tested on an ATI HD4000 series 512MB VRAM card,there is nothing happen and the HyperMemory works fine,but on NVIDIA GT215 card,with 3.5GB SSM when the Shipping.exe request texture memory during the startup,it instantly crashed at 512MB VRAM usage and popup the message.Seems like the SSM didn’t help anything for VRAM content buffering .
Tried lowering resolution not work at all.Besides the page-file size is not related with this even a lot of “Wise advisor” suggest to add that.Is there any BUGs in utilization the SSM of NVIDIA GPUs?