Nothing wrong with the old Lynnfield i5s, I had one in my main PC until 3 months ago. I also had some performance problems a few years back, but I
took Viagra replaced the CPU cooler as the standard Intel one quickly clogs with dust, causing the CPU to overheat and throttle. If you don't have an SSD incidentally, I can't recommend one enough. Makes a massive difference to performance compared with an old rust-spinner.
Anyway, I eventually replaced my old i5 750 system end of last year - I had had 8 years of use out of it, and play a fair few games, so it's done me alright overall. In fact if it wasn't for the increased struggling with modern games, I'd probably still be using it as it still motored through most other tasks with ease. My new system (Ryzen 7) is water cooled (Corsair H110i), and it handles temps very well indeed!
EDITED: 3 Mar 2018 12:15 by DAVE!!