In the memory department, the Z490 Taichi is performing as expected, especially when overclocked to the DDR4 4000 settings. At this frequency one could tighten the secondary and tertiary timings as per usual, but it was alarming not being able to do DDR4 4266 with the specific DRAM kit I had. That said, ASRock showed that they could get the same GALA HOF Arduino kit to run DDR4 4266 with little fuss. I have to conclude it is this specific CPU, DRAM and motherboard combination that didn’t work well past DDR4 4000 rather than the board not being capable. Your own luck will vary.