Unable to adjust memory speed; inconsistent RAM signals detected.
Unable to adjust memory speed; inconsistent RAM signals detected.
Hey there! I recently upgraded my CPU, RAM, and motherboard. I got the Ryzen 9 7900X, an ASUS TUF B650 Plus with Wi-Fi, and double 32GB Corsair Vengeance DDR5 6400MHz RAM. My PC is running smoothly and delivering great performance across all games I play. However, my RAM remains stuck at the default 4800MHz, even though my system handles everything well. Despite tweaking BIOS settings and searching online, I can’t adjust the RAM speed. From what I’ve learned, my CPU and motherboard should support 6400MHz, but there seems to be a stability issue when RAM exceeds around 5600MHz–6000MHz. After some more investigation, I discovered that Ryzen CPUs don’t always run stably at higher RAM speeds—sometimes they drop below 5600MHz. When set to 6400MHz, my PC crashes during startup and shows warning lights before the crash. Lower settings trigger a brief LED flash but allow me to boot Windows. Still, my RAM stays capped at 4800MHz. What’s odd is that when I reboot into BIOS again, it reads my RAM as running whatever I set it to. If I try to push it up to 6000MHz, Windows returns to 4800MHz, but after a restart, BIOS keeps showing 6000MHz. This inconsistency is confusing. My Task Manager displays the clock rates in MHz, which seems incorrect since MT/s should double the MHz value. I’ve also noticed mixed reports from NZXT and MSI about actual speeds—some say it’s accurate, others claim MT/s is misleading. My NVMe program shows half the claimed rate, while the command prompt always says 4800MHz. I’m unsure if MT/s is a reliable metric or if there’s another way to measure RAM speed. Another frustrating point is that my BIOS lacks XMP support but uses DOCP instead; previous attempts with XMP didn’t work. I’ve tried all three DOCP profiles, but none function properly. I’ve set my RAM to every possible frequency from 4800MHz to 6400MHz, and only 4800MHz works consistently. My PC and motherboard are up to date. It’s perplexing—my system runs perfectly, yet I’m stuck with such limited RAM speeds. Maybe my research was off, or perhaps the parts didn’t fit together as expected. I’m just a gamer who values performance, but this issue isn’t trivial. I hope I can resolve it before it affects my gaming experience.
Notice that all profiles are configuring my RAM to 6400MHz with the target DRAM frequency displayed in yellow at the top left. On the right side, the memory frequency shows 5600MHz as I manually set it before. Despite the BIOS indicating 5600MHz during boot, it immediately drops to 4800MHz. I've tested all three DOCP profiles, but none function properly. It began in auto mode, which resets RAM to stock settings. After switching back to auto, it remains at 4800MHz regardless of the manual frequency adjustments. Even when I set a lower frequency manually, it always reverts to 4800MHz.
I’ve researched further and discovered that listing RAM as DDR5 6400MHz is misleading. It’s not accurate to say it’s at 6400MHz either—it’s more about megabits per second (MBPS) rather than megahertz (MHz). My system is actually operating at its peak, running around 6400MBPS and 3200MHz. I suspect some sellers just list MHz for simplicity, even though it doesn’t reflect the true speed. I hope others who are confused can find this information and understand better.
You're puzzled because your system claims a different speed than what you're seeing. Check the Task Manager to see the actual numbers displayed there.