Big difference in RT-N66U up/download speed

[mrkni]

Hello,
I bought RT-N66U last week and it is wery good router at first look. But I have problem with wireless speed.
My router is set to Infrastructure and operate on 5 GHz frequency only with 802.11n mode only (Channel bandwidth: 40MHz). There is no other wireles device in network and there is no other router operating at 5 GHz. Security is set to WPA2-PSK and encryption to AES.
When I send 1 GB file from my PC to router ( to USB Flash disk, USB HDD or NAS), the speed is only 5 MB/s, but when I receive 1 GB file from router to PC, the speed is 12 MB/s (which is good). When I test speed with Lan speed test, i get 112 Mb/s writing and 100 Mb/s reading. So, where is a problem?
Router is 5 meters far from PC.
My wifi card is TL-WDN4800 and I contacted TP-Link support, but we find out, that the problem isn´t in my PCs wifi card. They told me to force wireless speed in router, but there isn´t such option. There is only "Multicast Rate" but with maximum speed 54Mb/s.
My firmware is .112 and same speed is with .108. And I tryed restore settings.
Does anybody know how to solve this?
Thanks for your answers.

 

[thiggins]

Check your read/write file copy speed using a wired connection between the same PC and router. Be sure you disable wireless in the PC when you run the test.

 

[mrkni]

Wired connection is about 700 Mb/s. Problem is only with wifi an only upload to router. I can´t test internet speed, because i have only 10/1 Mb/s.

 

[thiggins]

I meant test wired speed using the same file transfer setup, i.e. between PC and the router's USB drive.

 

[mrkni]

The speed is 140 Mb/s upload and 130 Mb/s download, but i tried to copy this file throw wifi into my lan connected NAS and the speed was 5 Mb/s too. Other connection types are ok.

 

[RMerlin]

The speed is 140 Mb/s upload and 130 Mb/s download, but i tried to copy this file throw wifi into my lan connected NAS and the speed was 5 Mb/s too. Other connection types are ok.

There's a known issue where the router QoS will interfere with Wifi2LAN transfers. Make sure QoS is disabled, and try again the same transfer over wireless.

 

[mrkni]

QoS is disabled all the time. I dont use it.

 

[mrkni]

I have just discovered that when I copy 2 GB file throw wifi into my NAS with FireFTP (firefox plugin), I have speed 17/18 MB/s (Download/Upload). When I copy same file with windows explorer, speed is 20/28 MB/s. And with Total Commander, speed is 15/5 MB/s.
So the problem is maybe in TotalCMD. I try to do some other tests and refer back.

 

[mrkni]

The problem was only in Total Commander. This is old problem, but everything was ok until I bought this router. Solution is easy:
In "C:\Users\<username>\AppData\Roaming\GHISLER" find file "wcx_ftp.ini" and place there line "UploadBlockSize=32768" under the [General] line like this:

[General]
UploadBlockSize=32768