How dependent is PPSSPP on my computer's VRam?

[tintinmayo]

I'm using an Intel HD Graphics IGP meself (see sig), and I've tried to set the shared RAM to different settings to ensure that I will only use the absolute minimum that PPSSPP requires (so that I don't take up too much from the already measly 4GB.) The sweet spot in my case seems to e 512mb. Smooth sailing all around as long as I don't go above x3 resolution or enable any upscaling.

If I set it to 1 GB, I don't notice any improvements (and it's too slow for x4 and x2 upscaling anyway, so I don't really need the extra VRAM.)

If I set it to 256 mb, it's workable but there are stutters, particularly in heavy FB effects. On 128 mb, the stutters are more pronounced.

IIRC, Unknown has a post somewhere that explained PPSSPP's VRAM usage and which settings will make it chug VRAM - basically, the biggest hoarder of vram is the texture upscaling, as it not only consumes more memory than the internal resolution but also scales its usage faster the higher you go up the multiplier.