Help me choose a new graphics card

So I am looking at upgrading my rig this summer to something with a bit more graphics horsepower. I am trying to decide between getting a Fury X or 2 390X cards to replace my old 270. I am looking to game in 4k with a minimum of ~40 fps with higher being obviously desirable but not required. I am not opposed to the 980 ti but would rather like the adaptive refresh tech without having to pay so much for a monitor (getting the 24" pls samsung 4k monitor that is coming out at the end of July which has freesync). I guess what I am asking is which option would give me a better bang for my buck? I am not all that impressed with the Fury X once the hype is aired out, but it is a decent card for the money from AMD, but would getting 2 390X cards give me better frame rates and how will DX12 effect the dual GPU scaling? I have a budget of around $700 to spend on this project. Thanks

The initial benefit of DX12 will be similar to Mantle in that it will help to eliminate any CPU bottleneck, so while this may help with scaling, honestly, we won't know until we actually have the product. (Anyone feel free to prove me wrong here, I am by no means an expert.)

Two R9 390X's probably has the performance advantage over the Fury X. For a similar performance measure, you could take a look at the R9 295x2 benchmarks to get an idea of the ballpark performance. Keep in mind, you will have to deal with the splendors and pitfalls of Crossfire.

I would get a 390. Do not pay more than $350 on a video card :). They depreciate pretty fast.

2 390s would likely give you the best performance. The Fury X is sold out everywhere right now and some speculate that it won't really be widely available any time soon. The 8gb on the 390 makes it a great choice for an SLI/crossfire set up. You just have to make sure that your psu can handle the draw and that your case can get rid of the hot air that the card puts off.

I was kind of thinking that the 390s would be better than the Fury X based on the benchmarks I've seen between the two. I do plan to keep these for likely 2 years unless there is something next year that is a total game changer and puts everything else to shame for a decent price, so that is why I am not too concerned about the cost. Do it right the first time and don't have to spend more than needed fixing mistakes and such. I was wondering though if there was any real substantial difference between the X versions of the cards beyond the clock speeds. Could I go with the non-X version and over clock them (as I planned to do anyway) to get them at least close to the speeds of the X versions?

I have an EVGA 750 watt PSU and I know it can handle a single card, but would I need to upgrade to a larger PSU for a crossfire set up? My system is running an 8320 Over clocked with an AIO cooler, but not really much of anything else power intensive in the system (An SSD, HDD, rarely used CD drive (lol i know, but I still get CDs occasionally), and 5 fans). And thanks for the quick replies!

I would do two 390s but you'll have to upgrade your psu to 1000watt or more. Even if you sell your old psu on ebay and buy a new one you'll be over $700. But two 390s will out perform a single FuryX.... so it should be worth it. Its hard to say exactly what dx12 will do for gaming and performance at this point.

since the 980Ti and Fury X are currently arround the same price, its a hard decission.

I think that i would still go with the 980Ti, but yeah if you realy want free sync, then waiting for the Aftermarket Fury┬┤s could make more sense maybe.

Thanks for all the input everyone. I'm going to go with the dual 390X, but it will take me longer to get that set up going. Probably going to get just 1 card now with the monitor and then work on the PSU and second card in the black Friday sales.