I had a stable system with two 8GB Corsair DDR4-3200 sticks installed in slots 2 and 4. I added two 16GB DDR4-3000 sticks, making four modules total. The computer started normally and worked for about 15 minutes, then powered off and would not boot properly again—the fans spun, but there was no display or working peripherals. After removing the new memory, the computer worked normally. The motherboard is a B450 AORUS PRO-CF. What should I check to make all four sticks work reliably?
3 Answers
Test the new sticks by themselves first, using the recommended two slots from the motherboard manual. If the PC will not boot with only the new pair, test each module separately and try clearing the CMOS. Also check that the BIOS detects the memory correctly before enabling any memory profile. A BIOS update may help with memory compatibility, but it cannot guarantee that mixed kits will run together.
The most likely issue is instability from mixing two different memory kits. Even if the speed and DDR4 type are compatible, the modules may use different chips and timings, and four sticks put more load on the memory controller. Try disabling XMP/DOCP and running all four sticks at a conservative speed such as 2133 or 2666 MHz. If that works, increase the speed gradually. For the best reliability, use one matched 2x16GB or 4x8GB kit listed on the motherboard’s memory support list.
There usually is not a setting that simply skips memory initialization and fixes this kind of problem. The system still has to train and verify the RAM during startup. Start with XMP/DOCP turned off, confirm that every stick is fully seated, and run a memory test once the system boots. If errors appear or the machine remains unstable, use only one matched kit rather than combining the old and new modules.
The original two sticks are in slots 2 and 4, and I installed the new pair in the remaining slots. They clicked into place, but the system shut down after running briefly. Removing the new pair restored normal operation.