So you have a i7-4770K and you want to upgrade to a i7-4790K? Am i missing something? That would be just stupid. If you have temperature problems when overclocking the 4770K, 1st thing is to use a good aftermarket cooler. And if that isn't enough, look into delidding the cpu to keep it cool. Seriously, if you just overlock your cpu to something like 4.4 Ghz, it should be faster than any not overlocked cpu you can buy.
About the settings, as everybody already mentioned, use HLE audio, it is much faster. Only if you get audio problems, like stuff not sounding right, then use LLE audio. Also disable forcing ntsc-j, if the game is not japanese.
You can try enabling per pixel lightning. Usually this should make things slower, but if it makes things faster, there is definitely a problem with your gpu entering high performance mode.
About upgrading your GPU: That shouldn't be necessary, i have an amd radeon hd7790 and i play everything just fine on 3xIR. Your gpu is 100% to 300% faster than mine according to benchmarks, so if you are fine with 3xIR, any faster gpu would be pure overkill.
About directx errors: If either directx or opengl does not work in Dolphin, you have either a hardware or a driver problem. Try some driver uninstaller, that completely removes your gpu driver, and make a fresh clean installation with the lastest stable driver. And if that doesn't work, try the lastest beta driver.
Last but not least: Try making a portable configuration. This allows you to test with clean default settings, and also to test if the problem is storage related. Create a portable.txt file in your Dolphin folder(where the Dolphin.exe is located). Dolphin should use default settings without your saves and whatnot, that's what we want here. And then try copying the whole folder to your various drives and start it from there.
About the settings, as everybody already mentioned, use HLE audio, it is much faster. Only if you get audio problems, like stuff not sounding right, then use LLE audio. Also disable forcing ntsc-j, if the game is not japanese.
You can try enabling per pixel lightning. Usually this should make things slower, but if it makes things faster, there is definitely a problem with your gpu entering high performance mode.
About upgrading your GPU: That shouldn't be necessary, i have an amd radeon hd7790 and i play everything just fine on 3xIR. Your gpu is 100% to 300% faster than mine according to benchmarks, so if you are fine with 3xIR, any faster gpu would be pure overkill.
About directx errors: If either directx or opengl does not work in Dolphin, you have either a hardware or a driver problem. Try some driver uninstaller, that completely removes your gpu driver, and make a fresh clean installation with the lastest stable driver. And if that doesn't work, try the lastest beta driver.
Last but not least: Try making a portable configuration. This allows you to test with clean default settings, and also to test if the problem is storage related. Create a portable.txt file in your Dolphin folder(where the Dolphin.exe is located). Dolphin should use default settings without your saves and whatnot, that's what we want here. And then try copying the whole folder to your various drives and start it from there.