The Supermicro X9SCM-F isn’t a bad board for your home ESXi configuration, but it needs a tweak to get both NICs working properly. There’s three nics, with one of them being dedicated IPMI. The other two are Intel 82579LM and 82574L. The 82579LM isn’t detected by ESXi and the best way to fix that is to install a new driver for it. I was lucky and somebody had done the hard work and posted it on HardOCP for me.
http://hardforum.com/showthread.php?t=1607992&page=6
1. Install your machine(s) with the vanilla ESXi 5.0 ISO.
2. Log on to the console (or via ssh) of one of the machines and install the vib file by using the following commands:
esxcli software acceptance set –level=CommunitySupported
esxcli software vib install -v http://files.v-front.de/net-e1001e-1.0.0.x86_64.vib
3. reboot, configure all NICs, and try to enable FDM then