@antantti
Our plan is to invest on a HD 7990 or 2x R9 280X in the future. Or is other good options for mining? Will the Celeron and that motherboard will able to run smooth with 4 GPU's mining? We will buy those adapters PCI 1X to PCI-E 16X on Ebay. And I guess I will try both Windows and Linux and see what are the advantages and disadvantages of both systems.
@niksdt101 @Gohs
Well, winter is starting here in Portugal. We will have room temperature for about 16-17 ºC MAX everyday. But we will buy 4 FANs for 10$ to be sure everything runs cool.
I'm still the highest bidder on this one, no idea why no one has shown interest, maybe cause the card is...really ugly, but a 390x is a 390x. Take it from me if you want, i'm unlikely to purchase anyway. You'll need a PO box/family member/friend to receive it for you tho.
http://www.ebay.com/itm/VisionTek-Radeon-R9-390X-8GB/172911927943?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m1431.l2649