EFB access causing extreme performance impact

[gouki]

My machine is a Intel i7 4770k with a Nvidia GTX 970 (368.39) on Windows 10 x64 (1511) with the Stable Dolphin 5.0 build

The particular game in question is Super Mario Galaxy (though I'm sure it happens in other games too)

Having heard of the 5.0 release i was anxious to try it out, and i started with one of my favorites - Super Mario Galaxy.

At first the performance seemed great until i started to play the first Galaxy (Good Egg Galaxy)

Every one of the display plugins (Directx 11, Directx 12 and OpenGL) causes extreme slow-downs while moving around and in certain scenes if EFB access is enabled - which sadly is the only way to interact with many things in the game through the IR-cursor.

Each of the screenshots was made with a 4x internal resolution and the default settings 


OpenGL with EFB access from CPU


OpenGL without EFB access from CPU




Directx12 with EFB access from CPU


Directx12 without EFB access from CPU




Directx11 with EFB access from CPU


Directx11 without EFB access from CPU




Walking a bit to the right with the character apparently causes the scene to change and a lot less EFB calls to be made




OpenGL with EFB access from CPU


OpenGL without EFB access from CPU




Directx12 with EFB access from CPU


Directx12 without EFB access from CPU




Directx11 with EFB access from CPU


Directx11 without EFB access from CPU



Is there a particular reason for this slowdown that I'm not acknowledging, apart from the obvious flood of EFB access in scenes like that - an option maybe that I'm missing ? A bug? My system?

Either way it makes the game unplayable at non-native resolutions and moving around makes it much worse and non-fullspeed a lot of times. Forget about using LLE. 

[JosJuice]

That's just how EFB access is.

[KHg8m3r]

It's more demanding at higher resolutions. Try turning down some of your settings.

[StripTheSoul]

That's also a spot that's extremely rough because of that bright galaxy light whatever thing behind that tower (it's still being rendered, even if the tower covers it).