Eight distinct RAM configurations to accommodate 128 GB of memory.
Eight distinct RAM configurations to accommodate 128 GB of memory.
CPU model: 13th Gen i9-13900K. Motherboard: ASUS ROG Maximus Z790 Hero. RAM setup: Two 64GB kits of Trident Z5 RGB DDR5-5600 (32GB each). Specifications include CL28-34-34-89 1.35v. The claim is that memory suppliers must offer a single 32GBx4 package in one kit, with guidance for the board maker. "G.Skill Support" denies selling four DIMMs or planning a 64GBx2 kit soon. Task: Adjust BIOS settings to allow all four DIMMs to be installed together, then run MemTest86 four times. Expected performance grades: C at 4800 MHz, B at 5200 MHz, A at 5600 MHz, A+ above 5600 MHz. Note: Consider moving this post to another forum if needed. Updated March 7, 2023 by daveedmo55
Yes, you're asking a question. If so, I'm here to help. If not, feel free to clarify.
First of all, I’d like to remind you that if you don’t require 128GB of RAM, avoid using it! Stick with two DIMMs, return the other two, and save your money. It’s just a waste and doesn’t really boost performance. If you truly need that amount of memory, chances are you’ll prioritize stability over speed, so going with whatever the board is designed for will be the smarter choice. But if you genuinely need it to achieve maximum speed, this is the path to consider—it’s not particularly difficult. What you’ll face is the constraints of Intel’s memory controller. With high-speed DDR5, reaching top speeds is nearly out of reach. MemTest86 mainly checks DIMM health rather than controller performance. To push the controller, you’d need tools like y-cruncher VST. If you can run an hour on that, your setup is reliable and you can start analyzing timings. The key settings to tweak are VDDQ TX, VDD2, and System Agent (ASUS changes names but keeps the same meaning). These voltages have optimal ranges, but adjusting them further isn’t guaranteed to help and may even reduce stability. Since these clocks run low, a good starting point might be around 1.3V for VDDQ TX, 1.5V for VDD2, and 1V for SA—though these numbers are estimates. They shift with frequency and board specifics, so it’s mostly guesswork. The main point is to keep voltages below the safe limits: under 1.5V for VDDQ TX (some say 1.55V is okay), under 1.8V for VDD2, and less than 1.45V for SA. Aim for values lower than these, but be aware you’ll likely fall short. To test, begin with the original memory configuration, adjust voltages gradually, and monitor performance. If it fails after a few minutes of stress testing, revert to the last working settings, retrain the memory (usually by disabling fast boot), and ensure it survives the process. Once stable, you can fine-tune timings. Given the time and hardware limitations, it’s usually better to stick with what the board supports rather than risking failure.
Ronothan##, your feedback is appreciated! I need more than 64GB of RAM for this PC workstation to boost performance beyond what I already have. So far, I've tried these steps to expand from 64GB: 1. Added a 64GB module in slots A2 and B2 – MemTest86 passed. 2. Added another 64GB in the same slots – still passed. 3. Tried splitting the two 64GB modules into A2/B2 and A1/B1 – failed. Now I'm aiming for a total of 128GB. The speed is looking great!
Understood. Notifying you now. Gathering all the sticks and checking the label. Analyzing the memory codes—look for endings like "820A" or "821M." Ensure the last letter matches across all units; if not, select the model marked "M" and reorder your purchase. Adjust frequency to 3600 if variations exist, then follow the recommended configuration.
The third character holds no significance according to community analysis. The 8 carries meaning, the 2 has meaning, while 0/1 remains unclear. The M die poses a greater challenge for the memory controller compared to the A die, yet running multiple DIMMs simultaneously should still be feasible. I’d lower the memory speed to the maximum (3600) and test stability.
Thanks for your help on this matter! I had no idea that there were other numbers on the DIMMs that mattered regarding compatibility between the kits of RAM or regarding ease of use with the CPU's memory controller. Always something else to learn!