Im not sure, Ive loaded pfsense 2.0.2 and 2.0.3 on them and they are recognized just fine. Here is supermicro's site on them:
http://www.supermicro.com/products/system/1U/5015/SYS-5015A-PHF.cfm?typ=ENetwork Controllers
2x Intel 82574L Gigabit Ethernet
Supports 10BASE-T, 100/1000BASE-TX, RJ45 output