This issue is found since BIOS version 0823. (https://www.reddit.com/r/AMDHelp/comments/10ioxee/memory_performance_loss_on_am5_platform_after/)
Now I am on BIOS 1415, Asus Proart x670E with 7950X3D and two sticks of 32G RAM @6000MHz, EXPO enabled.
This issue is 100% reproduceable after resuming from S3 sleep, S4 sleep is not affected.
All AIDA64 memory benchmarks drop, especially read performance, 83GB/s drops to 69GB/s.
Tried to reset BIOS, enabled memory context restore, etc, did not help.
Is there any suggestions and technical support?
Please fix your buggy and buggy platform AMD.