I'm running a Ryzen 7 5700G on a Gigabyte Aorus A520 Elite with a Kingston Fury 2x8GB DDR4-3200 CL16 kit (KF432C16BBK2/16). I bought a second identical-looking kit to upgrade to 32GB, but the system refuses to POST whenever three or four sticks are installed.
I've already tried letting the system sit for memory training, clearing the CMOS, updating the BIOS, swapping the old and new kits, testing different pairs, and using both the recommended A2/B2 slots and A1/B1 slots. Either pair works by itself, and mixed pairs also work when only two sticks are installed. However, four sticks do not boot, and three sticks do not boot either. The system powers on with the fans running at a steady speed, but it never reaches POST and the motherboard's red indicator remains lit.
I believe the modules themselves are functional, since each pair works independently. Could this be a memory-controller or four-DIMM compatibility issue? What settings should I try—such as disabling XMP, lowering the memory speed, or adjusting SoC/VDDP voltage or ProcODT—to get all 32GB working?
4 Answers
Since both pairs work independently and the failure only happens with three or four DIMMs, the sticks probably aren’t defective. Populating all four slots places more electrical load on the Ryzen 7 5700G’s memory controller, and a DDR4-3200 setting that works with two modules may not be stable with two DIMMs per channel.
Start with one working pair, disable XMP, and manually set the memory to something conservative such as 2933 MT/s. Then shut down and install the second pair. Give the first boot several minutes for memory training. If it still fails, try the lowest default speed, around 2133 MT/s. If four sticks cannot POST even at that speed, the practical solution is usually a matched 2x16GB kit, since four-DIMM operation is not guaranteed just because the total capacity is within the motherboard’s listed limit.
If conservative memory settings don’t help, you can test a small increase to the memory-controller-related voltages. Some systems need SoC around 1.10–1.15V, and VDDP may help if it is set unusually low. ProcODT values around 43.6 or 48 ohms can sometimes train more reliably than Auto, though these are tuning steps and should be changed cautiously and one at a time.
This may simply be a weaker memory controller on this particular Ryzen chip. The fact that two sticks work in every combination but three or four consistently fail points more toward the CPU’s ability to drive four DIMMs than toward a bad module. A single matched 2x16GB kit is generally the most reliable 32GB upgrade.
Try running all four modules with XMP completely disabled and the RAM frequency lowered manually. Four DIMMs may need a slower memory speed than two, even when the kits have the same model number. Make sure the timings and voltage are also left at safe defaults while testing.
I was hoping to save money by adding another 2x8GB kit, but I’ll try lowering the speed and allowing more time for training before considering a 2x16GB kit.