EFB Copies RAM only playable over HDMI connection

[styckx]

Hey guys.. I actually had to turn to support.. This is a strange one

Specs in sig.. Running Dolphin 4.0-3419 as we speak.

This is my monitor setup.



Each monitor is 1920x1080..
Top one is HDMI (40in)
Bottom two are DVI (23in)

The problem.. I'm playing New Mario and send EFB copies to RAM so I get spinning coins and see the blue coins. I've been playing weeks now but I wanted to watch football so decided to play the game on one of the bottom monitors instead so I can play and watch football at the same time. When I run fullscreen on the upper monitor it's 60FPS solid at 2x Native. If I try running the emulator fullscreen on either of the bottom two it's unplayable stutter. For whatever reason I can't figure out I can only get playable results with EFB copies to RAM on the top monitor.

New Mario Intro screen top monitor: 60FPS
New Mario Intro screen either bottom two: Stuttering along at 25-30fps
New Mario Intro screen either bottom two with EFB Textures instead 60FPS

So, it's something with the EFB Copies to RAM specifically.

I can literally hit escape, drag the now windowed game down to one of the bottom monitors, click no on the "do you want to stop the emulation" dialog, fullscreen and it goes from 60 down to a stuttering 25-30 instantly. Restarting the entire emulator doesn't help.

Things I've tried

Disabling AV
Disabling SLI
Unplugging the top monitor
Unplugging the other bottom monitor
physically removing the SLI bridge
Reinstalling video drivers

Same results. EFB copies RAM only playable performance over HDMI.

It's only the emulator. I can load up Watch Dogs and blaze through at 60FPS solid.