Quote Originally Posted by jak3676 View Post
Having said that, the performance impact of single vs dual-channel mode is generally small - maybe a 1-2% difference in overall game performance for most games. However there are some games that are impacted more than others. In a quick google search, I could not find anyone who has done testing on WoW with the current BFA client. (sources: https://www.cgdirector.com/single-du...-threadripper/, https://techguided.com/single-channe...-quad-channel/, https://www.hardwaretimes.com/dual-c...ce-ryzen-3000/)
I'll be absolutely honest, I only quickly scanned those articles, but more often than not the tests:

A) Don't mix channels with an odd number of DIMMs (e.g. they're just testing single vs. dual vs. quad in a closed ecosystem)
B) Don't push a lot of RAM (e.g. solo player gaming performance)

With that, the question becomes, when she pushes beyond 32GB, then what happens? While multiboxing, are some of the games utilizing dual-channel and others not? Is that even a thing can happen, or does the machine just force the lowest common denominator across all applications, which would be single-channel? I don't know the answer to those questions, but if I had to guess, I'd say there is definitely going to be a performance hit in that scenario, in one way or another. Now, whether the user can actually feel the difference is going to depend on the user and how keen they are at noticing changes in their system, but until someone actually tests* using mixed channels while utilizing a lot of RAM across several running applications, I'd recommend that people avoid it where possible.

* Actually testing it with benchmarks, not feelings (e.g. the two configurations "feel" the same).