Due to a problem in the Intel® Quartus® Prime Pro Edition Software version 18.1, PCI Express* FPGA IP Core will have a functional issue if the HPS DDR External Memory size is extended from 2GB to 3GB for the Intel® Arria® 10 SX660 board if using Linux* Kernel 4.9.78.
To work around this issue in the Intel® Quartus® Prime Pro Edition Software version18.1, update the Linux* Kernel to version 5.10 or above.