Been out of the loop for a bit. Want to build sff system.

I just recently sold off my gaming system and want to go small form factor. Is an i3 to little for that or go with i5? I will be doing light gaming but nothing serious.

I need opinions on case, power supply, memory, etc. I found a used gtx 980 and a 24" 144hz monitor for super cheap, just need the rest. Thx

There is a Small Form Factor Systems forum right below this one that has more information in it especially on cases.

I would highly recommend waiting till next month for Coffee Lake. You will get 4 cores with the i3's, 6 with i5s, and 6 with HT with i7's.

Cores Threads Base Turbo Cache TDP
Core i7 8700K 6 12 3.7GHz 4.3GHz 12MB 95W
Core i7 8700 6 12 3.2GHz 4.3GHz 12MB 65W
Core i5 8600K 6 6 3.6GHz 4.1GHz 9MB 95W
Core i5 8400 6 6 2.8GHz 3.8GHz 9MB 65W
Core i3 8350K 4 4 4GHz NA 8MB 95W
Core i3 8100 4 4 3.6GHz NA 6MB 65W

As an alternative, if you're unwilling to wait for Coffee Lake or you want to build something as cheaply as possible, consider going with the recently-released AMD Ryzen processors.

The Ryzen 3 processors are all quad-cores and the Ryzen 5 processors each have six cores. Both sets of processors are each priced lower than their Intel "equivalents."

Intel still holds the edge in gaming performance, assuming that all other factors remain equal, but you can still game with Ryzen.