980 a worthy replacement of 2x7870 XT?

As it stands I have two 7870 XTs in my rig, pushing out a ton of heat and taking in a ton of power. I'm making the transition over to 4k as I fell in love with one I tried and have one on order right now (Samsung 590D), the TN Panel does not bother me as at my usual viewing angle it looks very similar to my PLS 1440p Korean monitor using a Samsung display. The question is I'm wondering if my 2GB of VRAM will be enough for 4k gaming, I've tried 4k on my rig but framerate was a little haywire at times but was still getting a fairly firm 60fps on Battlefield 3 with Ultra settings and no AA.

I'd also like to move over to Linux and as some of you are aware the graphics drivers are horrible for AMD and even worse for Crossfired cards, but this is a side benefit of spending the money on a 980. It is a lot of money and since 7870 XTs are somewhat obscure and barely known about as they run a Tahiti platform but I can find a somewhat good deal on a Zotac AMP 980. Is it worth spending the money or is it a silly idea?

 

Your current setup is similar to CFX R9 270's. Good setup for 1080/1440, not enough for 4K. About as powerful as a GTX 970, maybe a little bit more.

A single 980 is not enough for 4K 60 fps gaming. You'll want either two 980s or a Titan X.

Also, I'd keep Windows for gaming. You can dual-boot Linux and use it for everything else.

 

I would recommend around 4GB VRAM or more for 4K.