Very low speed with dlink dir655 and dwa-125 adapter

[coldwinter]

Hi everyone, hope you can help me on this.

I got a dir655 and previously used a belkin wireless adapter, but i was not happy with the speed and it was a G only adapter so i went and bought a dwa-125, thinking that i would be able to get nice N speed and since both router and adapter are d-link product i expected everything would just work.

Unfortunately the first time i hooked up the dwa-125 i only see a max speed of 64mbps which is not much better than my previous belkin adapter, so i went to the router configuration page and changed the channel width from 20 mhz to 20/40 auto, and voila....135mbps (note that i'm using g and n mixed mode). I was happy for a moment.

But then i noticed something very weird, when i start transferring files, the speed will drop to a ridiculous 13 or 5 mbps, and even when i am not transferring sometimes i could see it dropped to this speed. This is even worse than my previous wireless adapter. Note that my sister's laptop (which i guess is using some intel wireless) can get very good signal and constant 130mbps speed before and after i changed to 20/40mhz mode. The signal strength is also stronger with her laptop. I feel disappointed.

Here is my configuration of the router:
Firmware Version : 1.30WW, 2009/07/10

802.11 Mode :Mixed n and g
Enable Auto Channel Scan : yes
Wireless Channel : 2.437ghz -CH6
Transmission Rate : best (automatic)
Channel Width :auto 20/40Mhz

security mode:wpa personal
wpa mode:auto(wpa or wpa2)
cypher type:aes
Group Key Update Interval:3600

Firmware for dwa-125WA-125_A2_v1.31

Does anybody know what is wrong with my config? or it is simply a defect of the wireless adapter, I'm seriously not impressed by the performance.

 

[Guest]

Don't use mixed mode if you have the option of n only.

 

[coldwinter]

hi fihart, using mixed mode because i have some G device around. Just called DLink, gonna do a 1-1 exchange tomorrow, hope it will fix that