Originally Posted by ADHDadditiv
His 2500K is still worth something, same as the motherboard. If he upgrades to the 4670k he will have the newer architecture and can still sell off his 2500k for a good portion of the upgrade cost. Then a few years down the road, you do the same thing. Then with the money saved from the upgrade, put that towards another gtx 780.
Well, that's a typical way to do an upgrade. But you are not explaining what the benefits of going from a 2500k to a 4670k are. The IPC gains are minimal and gaming performance is nearly identical. The only thing left is whatever benefits he will have from the Z87 chipset, but realistically he's on a Z77 board so not too much. If he did work that a 4770k would benefit him from having, and you recommended a 4770k. I could see as that being a worthwhile upgrade because you can utilize the extra threads and many tasks would be improved; especially newer games like BF4. However, you are telling him to go from one gaming chip to another. Seems like a waste of money regardless of what you recuperate from selling the 2500k and Z77. 1150 is only going to have one more architecture before it is abandoned completely - a Haswell refresh. So telling someone to upgrade because it's newer is not the best advice when its going to be dead before you even realize it. When a 2500k, at least for gaming, can take you all the way to Skylake. When actual improvements will be made and will be worthwhile.
Simply put, he's on 1440p monitor but only using one 780. If gaming is what he does with his rig, then the best bet would be a second 780 so he can at least get 60 frames or more.
Knowing what a person does with their computer, is the best way to determine if a person can benefit from a CPU/Mobo upgrade. When it comes to gaming even i7-920's on 1366 are still rocking, even for other tasks.