Dual Slot GPU

I found a i7 4770k + Z97I-Plus mobo + 128GB M.2 SSD for 95$ at a local used buying/selling webstore. I just want to know if this motherboard will be compatible with my current PC. I have a mATX case, and the Z97I is a miniITX mobo, so I know that it will physically fit into my case. However, I...

I have a decent computer which used to be able to run league on high. A few patches ago my league would lag a lot and I would be forced to turn down my graphics settings dramatically. I start a game fine but the longer the game progresses the more I lag. Is this a computer overheating issue or...