This Extra Slim (XS) v2.2 board provides 32MB of SDR SDRAM memory for cores requiring a large (>512KB) of memory. Although the DE10-Nano has built in DDR3 RAM, it has a high latency and is not suitable for the timings required of retro EDO DRAM. So if a core requires precise memory timings, then the onboard DDR3 cannot be used.
All my Extra Slim (XS) SDRAM boards have been checked under a microscope to ensure no solder bridges are present, then each MiSTer SDRAM board is cleaned in an ultrasonic bath to remove flux residue and finally each board is tested at 150 Mhz for at least 1 hour. Every one of my boards uses the higher quality Alliance memory chips as opposed to the cheaper and less reliable Winbond chips, high quality KEMET branded capacitors are used on each board.
You can be confident knowing each Extra Slim (XS) v2.2 MiSTer SDRAM board has been tested for over an hour at 150MHz using the SDRAM Board Test Service Core (Release January 30th 2021). I also test each with a number of computer and console cores in games to ensure no issues are present.