Best CPU upgrade for UE4 i5-4690 or i7-4770

Need to upgrade the CPU of a studio PC with the specific target of creating product interactive viz using UE4.
The PC currently does have i3-4160, 16GB RAM, HD 5450

The new GPU will be RX 480 or GTX 970
About the CPU wondering btw i5-4690 or i7-4770/4790

I will not code, but using blueprints and all the other editor features.

In your experience will feel really the difference btw a 4690 and 4770 to justify the extra 25% cost.

The 4770 is about 30% faster, but you’ll mostly see that when building lighting.

That’s useful to know, simplify the choice.
At home I’m using a i7-860 that’s in theory 50% slower in PassMark vs i5-4690, a question is if this +50% gain will be true also in UE4 Lightmass computation.
Btw wanting to offload the lighting computation to gpu using LPV, a RX 480 or GTX 970 will be enough to work efficiently.

Just noticed i5 4690 didn’t support hypertreading.
I suppose this will make a huge difference in Lightmass and shader compilation, or the difference it’s not more than 30%?

The i7 would likely be even faster in that case, for the multi-threaded operations

I would choose i7 to quickly process other demanding tasks in the future.