I also run a GTX 970 with a i5-3350P 4 core non-hyperthreaded cpu in a socket 1155. It is a great cpu for single player games such as Far Cry 4 and Dying Light, highly recommend them and will keep mine in the unit for a lonnnng time. I found that using 16GB for memory in the form of 4X4GB showed some promise of helping processing power, tho I had ample as it was, so I used the extra 8GBs elsewhere. I now use 8 GB but don't multiplay at this time, but IF I did, I would try out the extra memory if possible with some used stuff.
Also check out the Xenon series of processors as they use the i7 cores hyperthreaded and minus the graphics, and at least in the style of socket 1150 (alas, yours is 1155 socket model), will run with regular memory and gaming programs. I would suggest a used one from a good source, with a lot of likes, thousands. don't buy a new board and OS just to get one tho. What you have should be able to be configured by an experienced tech to play multis just fine with a few comprimises like more memory, better configuring, and choosing games that are oriented to your rig and brands. Check out how good the 1155 socket Xenons are at switching over to gaming from crunching from here or elsewhere at a forum with knowledgable techs.
Just configuring can make a lot of difference.
Even a 2.8Ghz I believe will outperform a 3.4Ghz IN A 32 player MULTIPLAYER GAME when it uses twice the amount of cores as in 8 vs 4, the i5s will only use the physical 4 cores, but the Xenons will hyperthread to 8 cores. This will help handle the large number of players in a multiplayer game of say 32 players, I would not go over that without a super rig myself, but I haven't multiplayed in a long time, the newer games like BF4 or BF3 can have 64 player runs. These games are mainly made for multiplayer gaming, with it not thrown in as an afterthought to a single player campaign game, which goes a long way into how they are coded and makes them easier to pute with.