I currently have an i5-4590 and was considering upgrading to an i7-4790k. Around what percentage improvement in speed in Dolphin do you think I could expect from this? I'm not interested in getting a new motherboard at this time and I believe this is the best fourth gen cpu for Dolphin. I have already checked out this spreadsheet, but I still wanted to hear some opinions.
https://docs.google.com/spreadsheets/d/1...76mBs/edit
Your current CPU is not bad, so really only highly demanding titles will really be improved. Both CPUs are Haswell refresh chips (Devil's Canyon) so the really modest changes to the thermal interface materials and other changes are present in both chips. The 700MHz on both the base clock and boost clock are going to be about what you would expect(up to 20%ish performance increase in games that need the increase) and if you both find a game that hits the 4790k at 100% on a core at max boost and you have sufficient power delivery and cooling to keep it at max boost you could possibly see that. In reality the performance gain is probably not going to be that dramatic on most games. The ability to overclock (if you have good enough cooling and your MB supports it) might give even more gains, but again it will be limited to games that need the extra CPU performance otherwise your not gaining anything at all. The last benefit comes down to the extra cores allowing for more background tasks running with Dolphin and having less impact doing so.
So can it be faster, yes.
Will it be faster, depends on the games you run. By how much, again it will depend.
Your CPU is not a bad one for Dolphin and really I would expect the i7 to have a larger impact possibly in other things you do on your system that might be more multi threaded dependent seeing a more dramatic increase, but it will depend on what else you want to do.