I recently bought a prebuilt PC with a Ryzen 7 9800X3D, Gigabyte B850M C motherboard, RX 9070 XT, 850W 80 Plus Gold PSU, AIO cooling, and 32GB of Corsair DDR5-6000 memory. I upgraded it to 64GB by adding two more identical 16GB sticks, so all four RAM slots are populated. The system randomly loses video while remaining powered on, and restarting it leaves it unable to POST or enter the BIOS. The only reliable recovery method has been removing the additional RAM, powering the PC on, and then reinstalling the sticks. It will boot normally after that, but eventually the black-screen problem returns. I initially had EXPO enabled, but disabling it did not resolve the issue. I use the computer for game development, so the extra memory is useful. Could this be caused by running four DDR5 sticks at 6000 MT/s, faulty RAM, the motherboard, or an insufficient power supply?
2 Answers
Running four DDR5 modules at 6000 MT/s can be difficult for the processor’s memory controller, even when the sticks are the same model. Try testing with only the original two sticks in the recommended slots, then run a memory test. If that is stable, add the other two and test again. You may need to run all 64GB at a lower speed such as 5600, 5200, or the motherboard’s safe default settings. Also make sure the BIOS and chipset drivers are current.
The power supply is unlikely to be the first suspect with an 850W unit, unless it is a poor-quality or defective model. The repeatable recovery after removing RAM points more toward memory stability, a DIMM slot or motherboard issue, BIOS compatibility, or a marginal CPU memory controller. Check that every module is fully seated, test each stick individually, and try the kit in different slots. Since this is a new prebuilt, document the failures and consider using the warranty rather than continuing to troubleshoot indefinitely.
I disabled EXPO, but the machine eventually black-screened and stopped POSTing again. Removing and reinstalling the extra memory still temporarily brings it back.