No onboard SAS. It’s E-ATX / SSI-EEB.
https://rover.ebay.com/rover/1/711-53200-19255-0/1?mpre=https%3A%2F%2Fwww.ebay.com%2Fitm%2FIntel-BB5520SCR-S5520SCR-SSI-EEB-12-x-13-LGA1366-REFURBISHED-BOARD-ONLY%2F202711739146%3Fhash%3Ditem2f328fab0a%3Ag%3AV3MAAOSwq-ddCj~X&campid=5338535236&toolid=20008
Also available - S5500HCV