Why are my 5GHz transfer rates so bad??

[cis]

Hi all,

I would very much appreciate any help/feedback with an issue I'm having. I recently acquired an RT-N66U router and have been following the advice in this forum as per it's configuration. I'm running the latest (and excellent) RMerlin firmware.

The specific issue I'm having is that my 5 GHz wireless data transfer rates appear to be very slow and and I can't figure out why. My wireless card (AirPort Extreme 802.11 a/b/g/n) supports a theoretical transfer rate of 450 mbps and I'm on a clear 5 GHz channel.

Inssider reports 450 mbps for the other 5 GHz ssid in my wireless neighborhood, so why am I only getting 75 mbps? My 2.4 GHz rates are 200+ mbps which is pretty good. For testing purposes I've made sure that all other devices are connected to the 2.4 GHz band.

I've attached some screenshots of an Inssider report and of my RT-N66U wireless settings. It's entirely possible (most likely probable) that I'm missing something completely obvious here - or misinterpreting the report?

Anyway, I'd really appreciate feedback from those more knowledgeable than I.

Thanks everyone

 

[nubyOz]

Hi,

Would try a lower and/or Auto channel as well as lowering transmit power.
Also ensure no other devices are connected to your 5GHzsuch as single stream and single channel devices (mobiles...).

Best to ensure 5GHz and 2.4GHz have different SSID, otherwise some devices might go from one to the other unintended.

Regards

 

[cis]

Thanks for your reply nubyOz! I've done as you suggested:

1. My 5ghz ssid already had a different name than my 2.4ghz ssid but I went ahead and gave it another name anyway...

2. Lowered the transmit power to 100mW...

3. Set channel selection to auto...

4. Turned off all other devices - network map shows my macbook pro as the only connected client...

5. Rebooted the router...

I'm in the same room as the router, have a clear view and there are no obstructions or other sources of interference (that I know of).

I'm still only getting 75 mbps. Another 5ghz ssid joined the neighborhood and Inssider is reporting 450 mbps for this this one as well.

This is really bothering me but I don't know what else to do. Maybe I'll just have to live with it?

 

[thiggins]

What is the client card itself reporting for link rate?

What are you using to test actual throughput?

 

[cis]

Thanks Tim,

My wireless card reports a link speed of 450 mbps.

To test actual throughput, I did a local ftp file transfer from my Synology DS to my Mac over the 5 Ghz frequency. 1175.3 MB transferred in 48 seconds which is just under 200 mbps.

The same 1175.3 MB file transfer over the 2.4 GHz frequency took 183 seconds (~50 mbps) which (I think) is close to the max throughput rate for 2.4 GHz.

So…my 5 GHz connection is ~4X faster than the 2.4 GHz connection. I guess I'm satisified with that but I still think I should be getting faster 5 GHz speeds (or am I just crazy)?

 

[jlake]

Try a different firmware.
I thought you said you were getting 75 Mbps in your original post. Confusing.

Try removing your old profiles.

http://kb.linksys.com/Linksys/GetAr...less_Network_Profiles_.xml&pid=80&converted=0

 

[thiggins]

So…my 5 GHz connection is ~4X faster than the 2.4 GHz connection. I guess I'm satisified with that but I still think I should be getting faster 5 GHz speeds (or am I just crazy)?

I can't speak to your sanity. But 200 Mbps is pretty good. Be happy.

 

[cis]

Sorry for the confusion. Inssider is reporting a 75 mbps link speed for the 5 GHz frequency and 200 mbps for the 2.4 GHz frequency.

Being new to this, I didn't think to do the file transfer test until after Tim's post - thanks!

Apparently Inssider is...confused.

Anyway, I'm happy with these speeds and thank all those who offered help.

 

[theirongiant]

The range of 5GHz is shorter than 2.4GHz, and 802.11n also does not propagate as far as 802.11g.

• How far away is the PC?
• What kind of rooms / walls are between you and the router?
• Are there tiles on these walls?
• Are there any large mirrors on these walls?

Tiles are adhered with cement (concrete is notorious for blocking radio signals), and mirrors are backed with aluminum or silver, which can also attenuate signals. Brick and concrete can attenuate wifi up to 12db for every 3 of thickness.

See this document for further details:
Propagation Losses Through Common Building Materials (2.4GHz vs 5GHz)