All this sounds like you should just grab the 4th Gen i7 for a good price (if the k ist much more, go with that as you'd get the higher automatic boost) and get happy for a bit more time.Thanks for the detailed post and questions!
As part of my GPU upgrade, I went from 180 W to 330 W adapter. The extra 150 W may all go to the GPU, I'll need to see how that goes...
They're about $100 on eBay. That's really why I asked the original question. It seems like going from two cores to four would be worth it to me if we can make it work.
Yes, I'm going to test before and after the new GPU install, with stress tests and while racing, to see how much power I have left for a new CPU.
The chipset is either H87 or Z87. I'm on vacation so I can't check. I'm not planning on overclocking because of power and heat limitations. The thermal management in the case is pretty good, but I don't want to push it, especially with the extra heat from the GPU.
I hear what you're saying about building a new machine with the good parts I have. However, part of the fun for me is tinkering with parts and getting the most out of what I have. I'm very pleased by the participation in this thread. Let's see how much we can soup up this old beater...
It will definitely improve your performance. Maybe not by that much and depending on the perspective, not worth the money but it seems that you wanna keep your case etc so yeah, you'll have a nice boost in performance but not be blown away by it.
A cheap 9600k(f) build would feel like going from a bicycle to a sportscar but the 4th Gen i7 would at least be a decent little car to move from A to B without getting wet in the rain