HD 7870 Crossfire dual-monitor issue

[Goshko]

Hi guys, so I built this PC for my uncle with 2 7870's in a crossfire setup (he already had one and wanted to crossfire them). The CPU is an i5-4670 and the mobo is an asus z87-a on a 650W Seasonic m12ii PSU.

SO because this was my first experience with a crossfire setup ... I have a few questions I would like to ask you guys about.

First off, this is the 7870 I got him http://www.newegg.ca/Product/Product.aspx?Item=N82E16814131546 to match his older Asus HD 7870.

So my first question is, when he plays minecraft, GPU 2 is like at 1-2% usage ... is it because minecraft takes no juice to run ?
I also tested on Skyrim and usage was split 50/50 on both cards.

He also runs a dual monitor setup that he likes to run in duplicate mode. His first monitor is plugged via the DVI input of the first card and the second monitor (an HD TV) is plugged via the HDMI connector also on the first card.

For some odd reasons, some games show on both monitors and some don't unless I put the game in window mode. Is this is a normal issue in a crossfire setup ?

Thanks guys

 

[rubenclavs]

AMD has a feature called Zero Core in which if you are playing soft games or browsing the web or doing office stuff, the Card goes Idle. As for you set-up with Minecraft it only uses the first card to power up the system.

For Skyrim, that is not really a GPU intensive game. So maybe, both cards doesn't need to full load to play the game.

How about try playing Battlefield or Crysis and post here if it uses both 100 percent load.