I test this situation:
2 boards x86 1.6Ghz with 2 sr71 (5Ghz) each board.
When try 1 link with wlan1<-->wlan1 I can reach 130 Mbps TCP!! But when I start bandwidth test with wlan2<--->wlan2 same time, then two links low to 20Mbps..
Link wlan1 : 5180 Mhz
Link wlan2 : 5800 Mhz