The Supermicro website does not list older BIOSes. It also does not list what has changed within newer BIOS releases, though Supermicro's support is fairly forthcoming with the information.
A list of BIOSes I have collected, and their changelogs:
Download v1.1b. MD5: 03e4a13d37188f1c31ff0c8ad980f594
- Fix a FAN control malfunction problem after AC loss.
- Enable workstation, quiet, super quiet fan control mode for 4-pin fan only for revision 3.1 board.
- Change revision to 1.1b.
- Pass BIOS CHECK 4.0.0
Download v1.1c. MD5: c5d7703c59013ecb719aedbf72b4c838
- Change FAN control by using FANOUT1 and FANOU2 instead of FANOUT2 and FANOUT3 according to hardware
- Change revision to 1.1C
Some important BIOS options I use:
- Memory settings
Node interleaving: Disabled (enables NUMA, effectively reducing latency for certain memory accesses)
Software memory hole: Enabled (remaps PCI DMA address space away from 4 GB, which effectively makes more RAM available to the OS)
Hardware memory hole: Enabled