A620M PRO RS doesn't boot with the EXPO 5600

Message Topic Search Topic Options Post Reply Create New Topic Printable Version Translate Topic

   Hi, I have an ASRock A620M Pro RS WiFi motherboard and 4 sticks of Kingston Fury RAM 4x16GB (KF556C36BWEK2-32) DDR5 5600MT/s CL36-38-38 1.25V.
The processor is a Ryzen 9 9900X3D.

The problem is that the computer only boots at the default 3600MT/s setting or with the selected 4800 profile. There are also EXPO/XMP profiles available for 5200 and 5600, but with those the system doesn?�t start, showing red CPU and DRAM LEDs. Sometimes it manages to reset and revert to 3600, but other times I have to remove the CMOS battery.

Are these RAM modules not compatible with this motherboard?
What can I do to make them work at full speed?

Author	Message Topic Search Topic Options Post Reply Create New Topic Printable Version Translate Topic
Jojczak Members Profile Send Private Message Find Members Posts Add to Buddy List Newbie Joined: 11 Jun 2025 Status: Offline Points: 50	Post Options Post Reply Quote Jojczak Report Post Thanks(0) Quote Reply Topic: A620M PRO RS doesn't boot with the EXPO 5600 Posted: 11 Jun 2025 at 1:16am
	Hi, I have an ASRock A620M Pro RS WiFi motherboard and 4 sticks of Kingston Fury RAM 4x16GB (KF556C36BWEK2-32) DDR5 5600MT/s CL36-38-38 1.25V. The processor is a Ryzen 9 9900X3D. The problem is that the computer only boots at the default 3600MT/s setting or with the selected 4800 profile. There are also EXPO/XMP profiles available for 5200 and 5600, but with those the system doesn?�t start, showing red CPU and DRAM LEDs. Sometimes it manages to reset and revert to 3600, but other times I have to remove the CMOS battery. Are these RAM modules not compatible with this motherboard? What can I do to make them work at full speed?

Jojczak Members Profile Send Private Message Find Members Posts Add to Buddy List Newbie Joined: 11 Jun 2025 Status: Offline Points: 50	Post Options Post Reply Quote Jojczak Report Post Thanks(1) Quote Reply Posted: 11 Jun 2025 at 5:13pm
	Okay, I?�ve done some research and now I understand. My whole life I was wrong, I thought the more RAM sticks, the better, but it turns out it depends. If we want maximum performance, we should use two sticks, if we want maximum capacity, then four. In the specs for the Ryzen 9 9900X3D and other Ryzen CPUs, it says that 5600 MHz is supported in a 2x2R configuration, but in a 4x2R setup, only the basic 3600 MHz is supported. So it?�s my fault for not reading the details. I returned the sticks and ordered 2x32GB instead, and I?�m leaving this message here for future generations.