Review on ASRock X570 Pro 4 - Advanced AM4/4DDR4/HDMI/DP/ATX Motherboard for Optimal Performance by Anthony Heinrichs

I contacted ASRock tech support a week ago but they don't answer! No acknowledgment of receipt, no message that we're investigating the problem. Here's the story: I bought the board in early December. First, 32 GB of Crucial Sport 2666 MHz DDR4 RAM were installed in slots A2 and B2. About a month after installation, I noticed that Windows 10 only recognizes 16 GB and another 16 GB is "hardware reserved". None of my online research found a solution to this problem, so I contacted ASRock support who said it was a Windows issue. Good. Again, searching for a solution to a Windows-related issue didn't yield any positive results. Running memtest86 resulted in no errors. I also tested other RAM modules with the same results. The last step I took was installing a stick of RAM in A1, then A2, then B2. Here are the results: A1, one stick = working, recognized by Windows 10 A2, one stick = working, recognized by Windows A1 and A2 (with corresponding dual channel pair) = working and full RAM is recognized by Windows. B1 = Booting, but only half of the RAM is recognized by Windows. Bottom line, I don't seem to have a problem with Windows (I even reinstalled Windows) but a problem with the motherboard; this. Memory banks B1 and B2 do not appear to be working. To date no response from tech support.