PPSSPP options explained

[vsub_]

What does Options=>Render Resolution=>?x Render Resolution actually do.
Can this option somehow decrease the game speed...the only thing I found about that option is that it changes the size of the ppsspp menus and the size of the ppsspp text messages while in game(vps\fps,standard,fixed and so on).

There is no difference in the menus and text between 2x and anything above...the window size is changed between 1,2 and 3 but between 3 and 4,there is no change.

I'm asking because I often see posts like "changing the render resolution fixed the problem".

And btw as a side note for the newui...all of the menus on the right side are missing at 1x and the menus at the top are acting as if you set the resolution to 2x or above