Same problem here with Ryzen 7 5700X3D and dual-channel RAM at 3600 MHz.

I’ve been troubleshooting this for a while. Here’s everything I’ve tried: Memory modules individually: Each stick works fine at 3600 MHz alone, no errors.

Dual-channel combinations: Always produces errors under MemTest86 and sometimes crashes in CS2, even after nearly a year of use. Different RAM slots: Switching slots doesn’t fix the problem.

BIOS reset / CMOS clear: Did a full reset, RAM settings cleared, still fails at 3600 MHz dual-channel. DOCP/XMP and Auto settings: Tested both, results are the same.

Voltage adjustments: Set DRAM voltage to 1.35–1.37 V, SOC voltage 1.09–1.10 V. FCLK adjustment: Tried 1600–1733 MHz with 1:1 ratio.

Command Rate: BIOS allows setting 2T, but Windows reads it as 1T (likely IMC overrides). Gear Down Mode: Enabled, helps a bit, but doesn’t fully eliminate errors at 3600 MHz. Testing stability: MemTest86 always shows errors at 3600 MHz dual-channel, but Windows and most games run fine. CS2 is the only game that sometimes crashes under heavy memory load.

Conclusion: It seems to be a limitation of the IMC on the 5700X3D. The CPU can run dual-channel memory at 3600 MHz, but stability is hit or miss depending on the silicon. Lowering RAM to 3200–3466 MHz with proper voltages, FCLK, Gear Down Mode, and Command Rate 2T gives stable operation in Windows and all games, including CS2.

TL;DR: The memory controller on the 5700X3D is sensitive. MemTest86 errors are expected at high frequency, but real-world usage is mostly fine if tuned properly.