Here's what I did

I have 2 7970 and a onboard video card.

At first I was using one of my 7970 HDMI to mine/browse on my computer, but I did notice it effect my harsh rate a bit (jumpy at 620kh/s - 580kh/s ish when I load stuff). So I was thinking maybe I should use my onboard video card to display instead, but when I switch the hdmi cable to my onboard, system wasn't detecting the 2 7970.

So I found a way to mine with my 2 7970 without effecting my harshrate and continue to browse on the internet with stable harshrate and without using a dummy plugs either.

1 HDMI from onboard to monitor, 1 DVI to vga from 1 7970 to the same monitor.

Set onboard screen as main, and 7970 as extend. Done (You can't just use 1 montior or it won't detect the 7970.)

Harshrate is stable at 620kh/s even when I load 5 tabs on chrome.


I am not sure if my 7970 will harsh even higher if it didn't have to render the extended screen. Might switch the DVI cable to my other 7970 to find that out.

Update: (It does not effect the harshrate unless you have something on that screen.)