I had a working system with two 8GB Corsair DDR4-3200 sticks installed in slots 2 and 4 on a B450 AORUS PRO-CF motherboard. I added two 16GB DDR4-3000 sticks in the remaining slots. The computer booted normally at first, but after roughly 15 minutes it powered off and then would not boot properly—fans spun, but there was no display and my peripherals did not respond. Removing the new memory restored normal operation. The modules appeared properly seated, and I checked compatibility beforehand. What should I try to make all four sticks work reliably?
3 Answers
Check the BIOS for XMP or memory overclocking. Four DIMMs put more stress on the memory controller, and a profile rated for two sticks may not remain stable with four. Disable XMP first and confirm the machine is stable at the default speed. Also check the motherboard’s supported-memory list and your processor’s official memory limits; the board may support the capacity but not the advertised speed with four modules.
Make sure the sticks are installed in the correct slot order and that every latch is fully closed. After changing the memory, clear CMOS so the board retrains the RAM. On the first boot, give it a few minutes because some systems restart several times while memory training. If it still fails, test the new 16GB sticks one at a time, then test them as a pair. A faulty module or an unstable mixed configuration could be the cause.
The most likely issue is running two different memory kits together. Even if each kit is compatible with the motherboard, the four sticks may use different chips or timings and fail when combined. Try resetting the BIOS/CMOS, then test each pair separately in the recommended slots. If both pairs work alone, install all four with XMP disabled and let the board use automatic, conservative settings. You may need to manually lower the speed, such as to 2666 or 2933 MHz, or increase memory-related settings only according to the motherboard and CPU specifications.
The original pair works normally by itself, while the system becomes unstable only after I install the additional pair.