1. The LSI controller has 1GB of onboard cache.
2. The CMOS battery is used to retain the BIOS settings if there’s no AC power.
3. LSI 2208 supports RAID 0, 1, 5, 6, 10, 50, 60.
4. The x540 has a PCIe 3.0 x8 connection from CPU1. Though the x540 only needs PCIe 2.0, the connection to CPU1 helps reduce latency. Supermicro and most competitors use USB 3.0 on our workstation boards, and USB 2.0 on our serverboards. Server customers typically use USB for HID, serial, or boot flash devices which don't have huge bandwidth requirements.
5. In the specs at the bottom, the SCU SATA ports can do RAID 5 as well.
6. The “schematic” is actually a component placement diagram.