First, a crucial clarification:
Visit the Intel Support for Boards & Kits page. Enter your AA number or the primary model number (often found near the PCIe slot) into the search bar. intel desktop board 21 b6 e1 e2 specification link
Once identified, use the specification links above to check: First, a crucial clarification: Visit the Intel Support
If you look at the back of your "21 B6 E1 E2" board, you will see: you will see: