30Mbit/sec via WiFi on 951G-2HnD 6.29 (Atheros AR9300)

RouterOS Wireless Networking
1

I have smthing strange on WiFi.
Interface: WiFi N-only, 5 clients.
Internet: 60Mbit/sec

/interface wireless
set [ find default-name=wlan1 ] adaptive-noise-immunity=ap-and-client-mode band=\
    2ghz-onlyn country=russia disabled=no distance=indoors frequency=2417 \
    frequency-mode=regulatory-domain hw-protection-mode=rts-cts l2mtu=2290 mode=\
    ap-bridge mtu=1492 name=WiFi preamble-mode=long ssid=AirNew tx-power=12 \
    tx-power-mode=all-rates-fixed wireless-protocol=802.11 wmm-support=enabled
/interface wireless security-profiles
set [ find default=yes ] authentication-types=wpa2-psk eap-methods="" mode=\
    dynamic-keys wpa-pre-shared-key= wpa2-pre-shared-key

Interface graph looks like a saw when i download large files on WiFi (see attachments) and current speed 145Mbit/sec
When i download same file via eth1 a graph is flat at 60Mbit/sec.

2

normal performance

in 2.4ghz you have to expect mostly the time only 20mhz works because of co-existence mechanisms.

normaly you have a peak performance of 20-40 mbit /second with good signal.

20 mbit on single spatial stream clients with good signal conditions.
40 mbit on dual spatial stream with good signal conditions.

if you want more buy a 5ghz ap to use 40mhz channels and doubling performance, or even 5ghz AC ap to get more boost using 80mhz channels but only if you have that spectrum avaliable

3

Also these parameters lower throughput :

hw-protection-mode=rts-cts

Not a good idea to set this on the AP side. It asks every time before using the air if it is free. It is useful on stations to diminish effects of hidden-node.

preamble-mode=long

Also this. Not such a big effect, but still lowers data rate.