A Core i3, i5, and i7 CPU’s from their 4th, 5th, or 6th generation is adequate for running Second Life. Using a 6th CPU gives you some future proofing. Otherwise the 6th gen offers little advantage over the previous generations.
The i5 and GTX 1060 I have runs Second Life with everything enabled. I pull a couple of things down from the ULTRA setting. (Draw Distance and number of impostor avatars.) Otherwise I’m running at ULTRA.
Using a 4th gen CPU now doesn’t mean you can’t upgrade later. With time the price of 4th and 5th gen i7 CPU’s will come down. The top of the line i7-5930k 5th gen CPU will perform as well or better than my i5-6600k and most other 6th gen CPU’s and some day for way less money.
It isn’t until we see 7th generation CPU’s that you’ll be outclassed. Even then, by how much is questionable. If you can run Second Life at 60FPS, does it matter if there is a faster CPU?
The i5-6600k is currently the best performance for the money 6th gen CPU, according to several sites doing benchmarking. That includes when they look at 4th and 5th gen CPU’s in the lineup. Once prices drop on 4th and 5th gen CPU that will likely change and for a time they will be the best for your dollar.
The only point that may strongly convince you to buy a 6th gen CPU now is Sansar. The new CPU’s and video cards are designed for parallel image processing, having two camera viewpoints, left and right eye for VR.
VR is going to be coming to consumers in 2017. It will likely have lots of rough edges and various problems. But, those challenges will start to shake out. Prices of VR headsets will start to come down. Competition in the field will increase. The free market will work its magic.
My thinking is I can play with VR using my i5-6600k and GTX 1060. They are not the top of the line. They are pretty much the bottom of the barrel for VR. A year from now I can upgrade to a more powerful CPU – 4 cores to 12, faster memory, and better video card. I should be able to triple the capability of this computer. I may find I don’t care for VR and won’t need to… unlikely.
So, I think the i5 way good enough for Second Life.