Computer.

You make to many topics on things you could just ask in the same. You ask this random questions on basic stuff.. Not to be rude but you should research at least some of this to have a basic understanding of gpu and cpu functions.

Can you rephrase your question?

Can a double i7 cpu computer beat a single i7 cpu computer?

Dual i7 / general consumer CPUs on a motherboard is not a thing. Outside maybe a niche motherboard generations back.

Xeons duals is a thing. Does it work better than a single i7 fourth gen?

Answer?

So many factors unknown that's it not possible to answer.
Yes dual xeons are a thing. Better in what way? What Xeon version? so it's possible to compare.
There will be a cache latency if both cpus working on the same task. That will show in games by fps.

The 1600 version that is comparable to i7 4790.

You won't see any benefit from running dual cpu socket boards in any average user tasks, which is why these setups are pretty much confined to the commercial server space.
Last consumer grade boards I recall doing dual cpus were from the X99 days (although there may have been a few ones later).

Unless you are doing cpu heavy server tasks, this is a pointless rabbit hole to go down. But if that is what you need it for, I would look into supermicro boards.