My mobo supports 128Gb of the following speeds and I want to try and fill each slot:
- DDR4-2133
- DDR4-2400
- DDR4-2666
- DDR4-2800
- DDR4-3000
- DDR4-3200
- DDR4-3400
- DDR4-3466
- DDR4-3600
- DDR4-3666
- DDR4-4000
- DDR4-4133
- DDR4-4266
- DDR4-4400
[Edit] Would 32Gb of ddr4-4000 or so be faster than up to 128Gb of a slower memory?
What is this system being used for? Unless you have very specific needs for a certain workload requiring huge amounts of RAM, you won't likely see any performance benefit from having more than 16 to 32GB installed. Today's most demanding games, for example, don't even need a full 16GB, and 32GB will likely be more than enough for running the next generation of games for many years to come. Unless you are doing specific tasks that you know can use more RAM, like certain high-resolution video editing workloads, adding more than 32GB will probably be a waste of money that could be better put toward other parts of the system.
As for RAM speed, DDR4-3600 CAS 16 is generally considered a good option for Ryzen 3000-series processors, as it generally doesn't cost that much more than the lower speeds, and tends to be widely compatible. DDR4-3733 may work fine as well, but is around the maximum limit that these processors can manage at a 1:1 infinity fabric ratio. Go above that, and additional latency will be introduced that may negatively impact performance, defeating the point of going with higher-clocked memory.