Performance constrained in specific expansion channels
Performance constrained in specific expansion channels
Today I encountered a strange problem. My system uses an Asus Strix B550 A-Gaming with a Ryzen 5 5600X. The RAM slots are labeled B1 through A2, with two dual-channel configurations: B1 & A1 and B2 & A2. Earlier, I had a G-skill Trident Z 2x8GB 3000MHz setup, placing the DIMMs in B1 and A2. The DOCP feature didn’t work, but I managed to set the RAM speed manually at 3000MHz without much concern. Recently, I swapped in a G-skill Trident Z Royal 2x8GB 3600MHz model into the same B1 and A1 slots. It started up normally at the default 2133MHz. When I attempted to enable DOCP, the system wouldn’t boot and returned to 2133MHz. I tried adjusting settings manually, updating the BIOS, changing timings and voltage, but nothing worked at 3600MHz. Eventually, I increased the RAM speed gradually from 2133MHz to 3133MHz, finally getting a successful boot. Now I’m puzzled—my RAM is supposed to be 3600MHz, yet it only reaches that speed when I manually set it. The manual mentions B2 for single DIMM and a 2 DIMM configuration in B2/A2, but it doesn’t specify that B1&A1 is the "inferior" dual channel setup. I realized this might be a misunderstanding, as my cooler doesn’t block RAM clearance in B1. I placed the DIMMs in B1 and A1 initially, then switched to B2 and A2. This change resolved the issue, leaving me uncertain about the manual’s guidance.
Depends on the MIC present on both the old and new sticks, as explained by Taiphoon Burner.
Yes, but A1 and B1 are also intended for dual channel. Nothing contradicts this and the bios will even tell you if you misplaced dimms, which it did not for that setup.
I don’t understand what MIC stands for in this context. Could you clarify the term so I can explain it properly?
The manual doesn't specify A1 and B1 as the main dual channel ports since they aren't considered primary dual channels. Manufacturers haven't utilized A1 and B1 for dual channels since DDR3 systems began. These slots serve as secondary options for extra memory, still functioning in dual channels. A2 is the single channel main slot. The reasoning behind this design is consistent across all manufacturers by default.
It's the memory IC, the chips inside the sticks. Not every memory IC works correctly with Intel and AMD.