These are my results. Have not tried to do any tuning. Win 10 Pro has a USB 3 Asus AC56 in it using 5GHz channel 149 width 80 through one wall about 10 ft from router. The Linux box is Mint connected via a 1 gig Ethernet connection to the wrt1900ac v1. These were multple tests taking the best as the saved info.
Have not installed your latest build, currently running DD-WRT 30534 with drivers 10.3.0.18-20160804
iperf is
[ ID] Interval Transfer Bandwidth
[ 4] 0.00-10.00 sec 204 MBytes 171 Mbits/sec sender
[ 4] 0.00-10.00 sec 204 MBytes 171 Mbits/sec receiver
DD-WRT 30471driver 10.3.0.18-20160823-1
[ ID] Interval Transfer Bandwidth
[ 4] 0.00-10.00 sec 150 MBytes 125 Mbits/sec sender
[ 4] 0.00-10.00 sec 150 MBytes 125 Mbits/sec receiver
Kong DD-WRT 30465 (latest) driver 10.3.0.18-20160823-1
[ ID] Interval Transfer Bandwidth
[ 4] 0.00-10.00 sec 159 MBytes 133 Mbits/sec sender
[ 4] 0.00-10.00 sec 159 MBytes 133 Mbits/sec receiver
With your last release Davidc502 LEDE build LEDE Reboot r1297 / LuCI Master (git-16.217.35130-6a11f71) I had the following which was quite good.
[ ID] Interval Transfer Bandwidth
[ 4] 0.00-10.01 sec 214 MBytes 180 Mbits/sec sender
[ 4] 0.00-10.01 sec 214 MBytes 180 Mbits/sec receiver
As you can see I get better performance with the 10.3.0.18-20160804 on DD-WRT. Currently due to family health issues, not mine, I don't get a lot of time to test. Based on my DD-WRT experience I would guess that the drivers you have incorporated may not provide the performance that I have seen in the past.
Hope this info is helpful
--bill
(Last edited by bill1228 on 5 Sep 2016, 21:26)