Confirm your understanding of mixed RAM before proceeding.
Confirm your understanding of mixed RAM before proceeding.
Previously this year I increased my RAM from 2x8 GB to 2x32 GB. I've never used mixed RAM before, as it was a challenge a long time ago. Now I'm figuring out if combining the two sets is fine. My motherboard supports up to 128 GB, though I'm not sure about XMP compatibility. Both units are Corsair, 3600 MHz, with speeds of 18-22-22-42 and 1.35V. If I install them in the order 8/32/8/32, dual-channel should function properly. Assuming the system was set up with the 2x32 GB first, what happens if I exceed that amount? Does it slow things down or cause issues? Or is the memory distributed evenly across all four sticks? Thanks! (Happy holidays!)
AMD and Intel platforms differ slightly, depending on the model, making it hard to give a precise answer without knowing the specifics. Generally, two slots form a channel; for example, 8+32 in Channel A and 8+32 in Channel B yield 40GB per channel. Performance hinges on the motherboard and CPU memory controller. Manufacturers often adjust CPU performance based on the number of slots and ranks you use. You might be surprised if it functions well, but it’s unlikely to be a natural fit out of the box. Recent CPUs like Ryzen 5000 or Intel 10th generation are more likely to perform at higher speeds (3000+), whereas older generations may struggle with speeds below 2133-2666 or not work at all. You probably won’t notice any difference as a user.
Basically luck of the draw. Usually you cannot reach the max frequency. With zen3 4 sticks thats almost never happening anyway. Mixed kits even less likely. A decent chance itll boot up but also no guarantee as Ive had multiple cases of first hand experience with that. Best results is a kit, second best is identical ram, third best is matching as close as possible and anything beyond that is well just keep rolling dice well.
Typically, aim for dual channel throughout the entire capacity. The 32GB units are likely 2R while the 8GB ones are probably 1R, which means performance will vary between them. The main concern is whether it will operate at full speed with four sticks—this is uncertain and not assured. You’ll need to test it and observe. Do you have a scenario where 80GB of RAM is needed beyond 64GB? If not, sticking with 64GB seems safer.
Thanks for the support! I had to turn off XMP to make it function (good news, BIOS can reset memory overclock settings). At 2133 MT/s it might be a bit slow for games, and ollama couldn’t handle more than 40-50 GB of RAM without crashing. Probably better to skip the 2x8 modules.