Steves video his poor by his standards though, so much so I think he should remove it. It isn't news that performance increases with 4x8GB single rank or 2x16GB dual rank on Ryzen, like I said it usually does.
8GB sticks are (typically) single rank, using 4 modules enables you to use rank interleaving, you get the same thing with 2x16GB dual rank modules.
If you look at Hardware Unboxed latest RAM benchmarks, though not completely apples to apples you can see this is true:
EDIT -
With regards to the vid, Steve himself has noted that "it's to do with ranks", so nobody is disputing that aspect is present. It doesn't change the fact though that - at least with 8gb sticks - 4 gives more performance than two, which is why I clearly stated that "within the context of the video" it's about the number of sticks.
As for the graph, that's poor by your standards given that the highlighted sections compare two different speeds of RAM (3600mhz vs 3200mhz). So much so that I think you should remove it.
Here's a video where the comparison is made with RAM that is actually the same speed. Keep in mind that the advantage is going to grow if you swap out the 4x8gb sticks for 3600 CL14 sticks, an option that you don't have with the 16gb sticks:
https://www.youtube.com/v/up3F37XTNDo&t=20s As for Wendell's statement regarding the 5600X, it's an
indication of what
may be a sweet spot, so somewhat conjectural at this point in time. Regardless, I've been very specific in my comments in that I was referring to Ryzen 3 when making comparisons between 4x8 and 16x2 performance. We'll have to wait and see just exactly how R5 shapes up in terms of optimal RAM usage. It could be that the bloody things like 16x4 DR for all we know. As for Titi's upcoming build, It may also turn out that the upcoming G Skill 3800mhz, 16gb, cl14 sticks will be the best option. We'll just have to wait on the testing to see how it all pans out.
Probably not worth going down the rabbit hole any further as we're talking nominal numbers of frames per second either way, so other than it being a debate for tech geeks like ourselves it's probably a redundant discussion.