Mahesh Mdr iframes are isolated requests, I would have to check the memory model of the browsers but i think every frame is somewhat equal to its own tab but I really would have to read the technical specifications
I think it depends on what you're loading in the iframes and what their page requests are like so it's a classic additive vector for all of it
IFLT (IFrameLoadingTime)
IFLT1 + IFLT2 + IFLT3
but ofc it could increase some loads in theory because there are limits to concurrent browser requests .... again I would have to look up how frames are handled from a process / thread perspective.
sorry :)