Slow download, high upload speed. Asus RT-N56U

[samuelrh]

I use the 5Ghz mode and am stunned by the fact that the download speed is less than half the upload speed. I get 34 Mbit/s downstream and 95 Mbit/s upstream.

If I go by wire instead I get both upload and download > 95 Mbit/s.

Since I get 95 Mbit/s upstream I conclude there is no problems with the wifi signal? I have only one client connected to the network, so no other client is stealing bandwidth.

What could cause this? Is there any settings I should change to get the download speed as high as the upload speed?

I´ve tried disabling the firewall, but that didn´t solve the problem.

 

[L&LD]

What firmware are you running? What client are you using? (Please don't say it is a handheld device).

What tweaks have you made to the settings, if any?

Where is the router positioned? Do you have it at least 10 feet above ground (not just the floor)? Is it clear of obstructions all around it (1 foot minimum and three feet preferred in 3D - so, not in a closet or bookshelf)? Have you physically tried to position it slightly differently and see if there was any performance gain?

Have you tried different channels to see which offers you the greatest throughput?

Do you have the Preamble type to long or short?

If all the above are at optimal settings, then consider the following.

Download and install the Padavan / moonman firmware for this router. And make sure you reset to factory defaults and do a manual and minimal configuration to secure the router and connect to your ISP.

Locate the router as indicated above.

Test for highest throughput on each channel manually. Ignore what programs like inssider might suggest. And make sure such programs are not running (they interfere with the throughput that can be reached). Simply change to the first available channel, reboot the router and record the throughput** (up and down). When you have a table of all the available channels, you will be able to easily select the best one.

** Make sure you are testing from a directly connected fast wired computer (with an SSD) or a multi bay NAS (4 drives or more in RAID5 or faster) to a wireless laptop that is kept stationary for all the tests to have meaningful comparable results.

 

[samuelrh]

Thanks for a swift answer.

Firmware Padavan 3.4.3.9-091
Client iMac 2014, OS X 10.10.2

No tweaks that I know of.

Since I get 95 Mbit/s upstream and the router is 3 meters from the iMac, with no obstacles, I can´t imagine the problem has to do with signal strength? If the signal strength were the issue, I assume the upload speed would be as bad (34 Mbit/s) as the download speed?

What I wonder is if there are different settings for receiving/transmitting (upload/download) since the speed vary that much? Are there specific settings that are only related to wifi receiving (since everything works fine if I connect the iMac to the router by cable instead of wifi, and since the upload speed is just fine)?

 

[L&LD]

Not signal strength per se, but more of how much invisible interference is on the channel(s) you're using. Keep in mind that other devices operating in the same frequency and channel may not be WiFi devices, but they will still cause issues with your network. Try them all and pick the best one.

What is the performance on the 2.4GHz band and the best channel (1, 6 or 11)?

With the apple connection, can you disable power savings on the imac? This seems to be a recurring issue with mac users lately.

 

[samuelrh]

I thought that since it works good enough to give me 95 Mbit/s upstream it should have the potential of giving me the same speed downstream? Are different channels used downstream/upstream, if not I wonder how it´s possible that the speeds differ that much? Could devices that interfere with my network selectively interfere with only the download speed (or vice versa)?

I have no power saving enabled on the iMac.

If I switch to 2.4 GHz I get 25 downstream and 10 upstream... What makes the in- and out speed differ like this? I´m on a 100/100 Mbit/s fiber connection, and when connecting to the router through ethernet, I get consistent up- and download speeds at around 95 Mbit/s.

So, are there are different settings for wifi receiving/transmitting?