components help

[grchina]

Hi forum i am in need of your help,i am moving to a student dorm where i would have free electricity in a few days and would like to setup a eth mining rig with 2x rx470  8pin sapphire 4gb cards.So i need your help about what motherboard and psu to get,was planning to use my old i3 cpu with 1155 bracket and 2x4gb 1333 mhz ram+1tb sata 2 ssd and old mini atx tower.Yes i know i could mine much more with pro btc mb and 6 cards but my room doesn't have space or ac to support it .Motherboard can be second hand and I don't plan to expand rig in the future so there is no need for a 1200w psu.Thx in advance

[BlueChinchillaEatingDorito]

I wouldn't even bother with 2 RX 470s on a Sandy/Ivy Bridge Core i3 and 8GB DDR3.

[grchina]

Can you tell me why not?I was  going to by 1 card and friend would give me second,if I  did my math right 1card would earn a bit less than 2$ per day.I would see return in 3 months and profit after that about 100$ monthly,considering that average pay in my country is 200...