Nobody knows. They are both quad core processors as far as benchmarks are concerned (the "Octa" is 4 A15 cores plus 4 slower A7 cores, with only one or other set used at any time). And unless it's a pure CPU benchmark you need to consider other elements of the system - we've seen often enough that different phones with the same processor and clock speed don't always produce the same benchmarks.
Most importantly, benchmarks have only a loose correlation with real world performance, so actually aren't really important. People geek on them because they are numbers which can be compared and look more "objective" than assessments of responsiveness, lag etc, but that doesn't mean that they are necessarily meaningful. Wait until we have samples of both and see whether it actually makes a difference, and if so to what aspect of performance.