Question Why can't I add 128gb of RAM to my motherboard?

[brandonmacleod21]

I recently added 64gb of RAM running at a speed of 6400mhz. My computer was stable so I then added another 64gb of RAM (128gb) and I noticed that nothing was showing up on my PC when I booted it up. It's been running for 7 hours now and nothing has posted yet. I also tried turning off Extreme Memory Profiles in my BIOS settings and that seemed to have worked but now the RAM speed is only 3400mhz again. Is it not possible to add 128gb of RAM at the speed of 6400mhz? My motherboard is the B650 Aorus Elite AX (AM5). Here are my other specs.

CPU: AMD Ryzen 9 7950X
GPU: Nvidia RTX 4090
OS: Windows 11

 

[Eximo]

Memory is sold in kits for a reason. Yes, it is highly likely you won't be able to manage 6400 with 4 memory sticks.

Manually tuning the memory to something like 5600 or loose timings at 6000 may work. With the added memory sticks you may also need to increase the DRAM voltage slightly.

 

[Lutfij]

Populating 4 slots on the motherboard would mean adding stress to the integrated memory controller at those frequencies. You can try and lower your frequency to baseline and not X.M.P but your results can be hit or miss.

You didn't mention the make and model of your ram kit(s) nor the BIOS version for your motherboard.