E4200 only hitting 54Mb/s on 5GHZ

[derekcentrico]

I ended up with an RMA for a new E4200 ver. 1 and the problem I have still persists.  My 2 GHZ WAP gets 65Mbp/s to its connected devices.  However, the 5.4 GHZ WAP gets 48 to 54 Mbp/s only.

My laptops have Windows 7 and Ubuntu.  The WiFi cards are Intel Centrino Advanced-N 6200 and 6230.  Both fluctuate at 48 - 54Mb/s on the the 5.4GHZ channel.

If I put it on Wireless-N only, the laptops cannot connect.  I have tried AUTO detection for mhz and channels.  I have tried 40mhz with channels 149 and 161 with no difference.

Currently, I am operating both WAPs on different SSIDs to make sure my results are separate.

Security for both WAPs is WPA2-Personal with a 10 digit sequence.

Any advice out there?  Thanks!

[phibertron]

Make sure that WMM is enabled

It has been reported that Intel (and others) need WMM On to be able to connect at N or N only speeds, or at all

I can confirm this, as I had that problem with one of the my laptops

A creature of habit, I usuallly tweak things/turn things off, and in doing so saw the problem you describe

Enableing WMM solved it for me

[derekcentrico]

This seems to have helped.  Now I can connect at 144Mbp/s.  Any idea on how to get it faster?

Channels matter?  Mhz matters?

[lordstag]

144 would generally mean you are on 20mhz. On the 5ghz radio you should be safely able to use chanel bonding (40 mhz) without interference. On the 2.4ghz radio it is generally best left on 20mhz due to interference. Even though you can reach 300 mbps on 2.4 with 40 mhz, 144 will generally produce better results.

[derekcentrico]

Yeah, one device is hitting 144Mb/s and the other is at 300Mb/s now that I made both above changes.

WMM - enable

40Mhz - 5.4

Auto - 2

Could I expect it to be any faster?  Should I do anything else?

No actual channels are set.  It's on AUTO for all of them.

[lordstag]

At this point it is probably related to your wireless clients. Assuming both those are on 5ghz band, their wireless cards probably only support 1 (144 mbps) and 2 (300 mbps) streams rather than 3 (450 mbps)streams. 144 mbps is expected on 2.4 ghz at 20mhz cahnnel.

As a side note you should pick the highest channel for 5ghz and 1, 6, or 11 for 2.4. Auto is usually fine for 2.4, but to get the most out of 5ghz you should pick the highest channel

[gv]

Please make sure to write accurately. What you write is very confusing. There is a 2.4 GHz radio and a 5 GHz radio. There is no 2 GHz or 5.4 GHz radio. When you write 5.4 GHz it makes me wonder whether you mean 2.4 GHz or 5 GHz. I have assumed 5.4 means 5 GHz but I am not really sure.

144 Mbit/s on the 2.4 GHz band with Auto bandwidth setting is the best you will get in most places due to interference with other wireless access points in the neighborhood. Due to interference, it is often better to use a 20 MHz band instead of a 40 Mhz band. The latter would use approx. 2/3 of the total available 2.4 GHz band and would thus be much more prone to interference with other access points. That would basically mean you would get worse throughput on a 300 MBit/s connection than a 144 Mbit/s connection.

Thus, assuming I interpreted those numbers correctly you have the best possible connections.

[derekcentrico]

Sorry for the confusion.  

The laptop with the Adanced-N 6200 chip is holding 144Mbp/s constant.  This one is about 30 feet from the router and in a different room.

The laptop with the Adanced-N 6230 chip is holding 300Mbp/s constant.  This is about 15 feet from the router in the same room.

Both support dual-band.  I assume the 6200 is sticking with the 2.4GHZ whereas the other is using 5GHZ.  Both are set to mixed mode and to prefer 5GHZ if it's better signal.

[lordstag]

I thought you had them on seperate SSID's? You should be able to tell which SSID it is on

[derekcentrico]

I did have them on separate SSiD's.  I recombined the names because it was just easier that way and some guide I read suggested it since the Intel chips like to switch between the two bands as necessary for the best data connection.

What settings would you recommend per SSID to test from?

I appreciate all the input!  I'm new to the dual-band world entirely.