I have often heard the advice repeated over the years that the memory controller on zen 4 and zen 5 boards can’t handle overclocking four sticks of RAM, but I found myself recently with an extra two sticks of the ram I’ve got in my new 9800x3D system (socketed into an asrock taichi lite x870e board) and I gave it a shot. To my surprise, I slotted in the new extra sticks, booted into the bios and set the 6000 mhz expo profile and it booted up just fine after a short memory training. I didn’t futz at all with any other timing settings, and I left the dram performance mode set to AGESA default. Infinity Freq is set to 2000mhz and UCLK DIV1 MODE is UCLK=MEMCLK (aka 1:1).
The RAM in question is Crucial CP2K16G60C36U5B (CL36, 2x16gb kit, stock 5600mhz), and I have two separate kits that were bought from different retailers, about 3 months apart from one another.
I’ve validated the stability with a 6hr run in memtest and another couple hours in prime95, so it seems to be stable? I only just installed the sticks yesterday, so I haven’t been able to test more thoroughly beyond just letting memtest run while at work today.
Is this dumb luck, or is the advice about only using 2 DIMMs no longer relevant on x870?
Yes harder to overclock. Performance should be the same with equivalent settings.
But you shouldn’t worry, above 6000 improvements in performance are small, anything over is in the range of diminishing returns, especially with single CCD CPUs.
Great, well I’m thrilled that I can have 64gb at 6000mhz, I thought that was off the table unless I went for a 2x32 kit and left my other channel sitting empty
Only problem is now I need another kit to put in the machine these two were supposed to go in!
Mostly the “advice” is wrong. While Raphael and Granite Ridge’s 2DPC DDR5-3600 support’s below their 1DPC 5200 (Raphael) and 5600 (Granite Ridge), 2DPC 2R 6000 overclocks have been a thing since shortly after Raphael launch. It’s pretty simple really but somehow there seems to be a lot of confusion that overclocking 3600 to 6000 is less likely to be achievable than overclocking 5200 or 5600 to 6000.
5200 → 6000 GT/s is +15%. Similarly, 3600 → to 4200 GT/s is +17%. 3600 → 6000 is +67%.
With two DIMMs you’d run 1DPC, not 2DPC on one channel.
On Asrock motherboards, I’ve found various levels of success with four sticks, but I’m using my desktop as a workstation so I’m doing 4x32. Four high density sticks like that often posts at JEDEC standard speeds, and often will not POST at an XMP profile at all. I am usually able to creep up that much ram to about 4000-4800. On some systems I’ve over-volted and stayed under the XMP speeds to keep four dimms stable.
