What is the best gpu requirement for Eevee rendering engine

So i have a gtx 1080 it’s a super fast gpu so my question is does it make difference in rendering time if you have gtx 1080 or gtx 1060?
Also if you scene doesn’t feet in to the graphics memory Eevee will use the systems memory?

EEVEE uses the same methods as advanced game engines out there to render. This means “Rasterization”, which is an aproximation to the real “raytracing”. The engine is quite close to the “real deal” but will not be the same until the hardware accelerated raytracing (a.k.a. nvidia 2080ti feature) becomes commonplace, and this will take some time (years).

For now (until hardware supports it, that is), the more VRAM you have, the better, since rasterization requires the entire scene geometry, textures and shaders be in vram to work on it. There’s no workaround around this. That’s why hardware manufacturers are battling to get more VRAM in their discrete cards, but the costs are prohibitive, so probably 8GB is going to stay for some time. (If i recall correctly there was an effort to make a video card that use an SSD as VRAM, also there was an effort to produce a 16GB professional card, but it seems both died).

Gtx1080 or 1060, it doesn’t matter really, a 1080TI would have been better, but for eevee, i’ve seen good results even on my old GT750M with 2GB vram. of course depends on your scenes.