R9 290 and crossfired 5770s, It works but

So I have an AMD R9 290 (works wonderfully when it's on it's own) and I also have 2 5770's running in crossfire. I plugged in one monitor  via HDMI to the 5770s and I plugged in another monitor via DVI and at the moment they both work, drivers are installed, and all is well but what is exactly happening?

 

I get that they aren't in three way crossfire but I want to know what I can actually do and what happens when say I want to game on the monitor connected to the 290. I saw Linus's video crossfiring 290xs and 780tis but he used them as separate inputs for one monitor, he never did multi-monitor, wish he did because it seems to work. Anyway, what can I do with this kind of setup? I was particularly wondering if I can mine dogecoin with the 5770s while I game on the 290. Thoughts? 

Thoughts? http://linustechtips.com/main/uploads/monthly_05_2014/post-53068-0-85981300-1399174754.jpg 

Here is a pic of it.


Try running cgminer or whatever you use for doge and only telling it to use the 5770s.  Then try to game with the monitor plugged in to only the 290.  See if that works, just shooting in the dark here, I dont really know either.

Apart from mining there is no reason to have a setup like that, ditch the 5770's all together. My 2c...

Which is the Primary card of the system? If the 290 is the primary card, then gaming on it is no problem.

The other cards.... well the only use for them really is mining or expanding monitor input. (for either these uses, having them in crossfire has no benefit)

BTW: You should NOT have the 290 power connectors setup the way you do. Each connector on the GPU should have a dedicated line back to the PSU not a daisy chained connector. Using a daisy chained connector will either not provide the GPU with enough power or worse have to much resistance for the power draw, heat the wire up and potentially cause a fire.

i think linus maybe used a socket 2011 mobo with 2 plx chips for that?

That makes a lot of sense. Yes the main card is the 290 and actually it works very nicely while gaming (albeit at 900p while I wait for a 1440p monitor to come in from korea).  I'll get on changing the power connectors on the double.

A capable motherboard with PCI-e 2.0 at x16, x8, and x8 can be used to mine on the two x8 lanes while gaming on the single x16 lane.