Colorful claims that it can run a pair of its 16 GB iGame Shadow II DDR5-6400 memory modules in dual-channel at up to 9600 MT/s on an AMD Ryzen 7 9800X3D with a pretty stark overclock. This particular result was achieved with slightly stretched out timings, at CL30 vs the stock 28, and by running the UCLK and MCLK with the usual 1:2 ratio. Complete stability was achieved by dropping the overclock to 9200 MT/s with CL32, suggesting there was some instability at the bleeding edge. Read more about AMD Zen 5 and DDR5 in our article " DDR5 Memory Performance Scaling with AMD Zen 5 "
Colorful's testing was validated in RunMemTestPro, and Colorful ran a third test, this time trying to chase lower latencies by tightening up the timings, reducing the memory clock, and running the UCLK and MCLK in 1:1 mode, usually reserved for DDR5 RAM running at 6000 MT/s or less. For this test, Colorful swapped the CPU for a more powerful—and likely better-binned—AMD Ryzen 9 9950X3D, and it managed to achieve 7200 MHz with timings of 24-37-32-28 and 100% completion of the memory test, suggesting decent stability, even with the increased UCLK frequency. The overclocking team also managed to stabilize an overclock with 8900 MT/s and 34-47-47-47 timings. It should be noted that Colorful hasn't actually provided any benchmark testing results to show any performance improvements over the stock 6400 MT/s for this particular RAM kit, nor has it provided any of the voltages or temperature consequences that came about as a result of these overclocks, so it's unclear what the long-term viability or implications of these overclocks would be.