http://support.asus.com/cpusupport/list.aspx?SLanguage=en&m=M4A89GTD%20PRO/USB3&p=1
yes some of the fx series are supported.
FX-4100(FD4100WMW4KGU),3.6GHz,4C,95W,rev.B2G,AM3+ ALL
3027
Beta support only
FX-4170(FD4170FRW4KGU),4.2GHz,4C,125W,rev.B2G,AM3+ ALL
3027
Beta support only
FX-6100(FD6100WMW6KGU),3.3GHz,6C,95W,rev.B2G,AM3+ ALL
3027
Beta support only
FX-8100(FD8100WMW8KGU),2.8GHz,8C,95W,rev.B2G,AM3+ ALL
3027
Beta support only
FX-8120(FD8120FRW8KGU),3.1GHz,8C,125W,rev.B2G,AM3+ ALL
3027
Beta support only
FX-8120(FD8120WMW8KGU),3.1GHz,8C,95W,rev.B2G,AM3+ ALL
3027
Beta support only
FX-8150(FD8150FRW8KGU),3.6GHz,8C,125W,rev.B2G,AM3+ ALL
3027
Beta support only
says its in beta but supported so im unshur.
maybe email asustek.