[Carlanga92]

Router Model
Asus RT-N12D1
Firmware Version
DD-WRT v3.0-r54095 mega (11/22/23)
Kernel Version
Linux 4.4.302-st46 #27015 Wed Nov 22 05:50:38 +06 2023 mips

Im getting low wifi speed with DD WRT. It is the first time i try a DDWRT firmware.

On 20 mhz bandwith i can only get about 60Mb/s.
If i set 40mhz i can get 100. (my router has no gigabit ports).

I should be able to get 144 instead of 78 on 20Mhz. Maybe my router is using only 1x1:1 stream instead of 2x2:2? It looks like only 1 stream is working.

The crazy thing is that on my wifi client (windows), it says that it connected at 144 on 20Mhz bandwith (but i only get about 60) and 300 on 40mhz.

It is normal?

I have read msoengineer's topic. ( https://forum.dd-wrt.com/phpBB2/viewtopic.php?t=327595 ) but it is the same.

Channel is not the problem.
I have tried too only N, and mixed G/N.

[ho1Aetoo]

144Mbit link speed does not mean that it is possible to achieve 144Mbit throughput

and a link speed of 144Mbit proves that 2 streams are used

[Carlanga92]

[ho1Aetoo]

100Mbit is the absolute maximum that can be achieved with 20Mhz channel width under the best conditions.

The maximum throughput is always 2/3 of the link rate

If it is not due to poor WLAN settings.
I would immediately think of crappy hardware, the router has a 300Mhz processor, and the throughput is basically dependent on the performance of the processor.
and dd-wrt is not the stock firmware...

I doubt that the stock firmware runs e.g. with kernel 4

[Carlanga92]

The 300mhz processor isn't the problem.

I was testing.

144 is only from computer to router.


On wireless status on the router, i can see: TX rate 65M, RX rate 144M.

So it looks like if i set my MIMO Transmission FIxed Rate is on AUTO, it seems to be blocked at MCS7 (only 65).

If i force to MCS15 i get 100 on 20mhz without problems.

Why MIMO Transmission fixed rate on auto is blocked at MCS7?