R9-290 Crossfire question

[Haizan]

So I got a R9-290 Tri-X today already and the prices are coming down nicely, just a smidgen above 200 dollars. Thinking about getting a second one. I got a few questions, though.

This is my mobo: http://www.newegg.com/Product/Product.aspx?gclid=CO-jtP2Cub4CFahaMgodAGcAkw&Item=N82E16813130726&nm_mc=KNC-GoogleAdwords&cm_mmc=KNC-GoogleAdwords-_-pla-_-Intel+Motherboards-_-N82E16813130726&ef_id=U3p1iwAABHUpvh1F:20140519222135:s

Would it be enough, I'm thinking of the 2nd slot in particular in terms of enough PCI lanes. Second, my current CPU is an i5 Haswell (unclocked). Would I need to OC it in order not to get any bottlenecks?

Third, I'm getting a EVGA 850W G2 PSU. I'm guessing it'd be enough for two 290's and a (possibly) OC'd i5? Otherwise my system is just one single HDD, a single monitor and no external HDD or other stuff.

Feedback is welcome and appreciated. Thanks!

 

[MeteorsRaining]

Do not crossfire on x8/x4 MoBo, it'd bottleneck the GPU's potential badly. Atleast x8/x8 is required concerning the GPUs' power. For the sake of CFX you can put 2 GPUs there, but in real world the performance would be considerably worse. You shouldn't worry on your CPU (you don't need to OC just to eliminate bottleneck) and PSU (it's good enough even after GPUs and CPU is OCed.

 

[Haizan]

Hmm, so what would a good mobo be? I'm surprised that the 100 dollar mid-range gamer MSI mobo isn't good enough.

 

[MeteorsRaining]

The MoBo itself doesn't have any issues, but the lack of PCIe lanes on second slot will make the experience terrible in any MoBo with that config. Any board from Tier 2 or higher from this list will be good enough for x8/x8 crossfire:
http://www.tomshardware.com/forum/id-2383187/motherboard-tier-list-z97-chipset.html