RT-AC66U: 5GHz isn't really any faster than 2.4GHz. Dualband broken?

[woutf]

I can't seem to get good 5GHz wifi speeds from my RT-AC66U, they're only marginally higher than the speeds I'm seeing on 2,4GHz.

I've tested with a few smartphones, including the iPhone 5, which should be able to hit nearly 100Mbps, but I'm not seeing speeds higher than 55Mbps. I've also connected a Asus Zenbook UX31A, which should be able to achieve much faster speeds than a smartphone, but that tops out at around 60Mbps. The linkspeeds are fine though: the laptop indicates 300Mbps and the iPhone around 150Mbps, but the actual speeds are much lower.

The weird thing is, when I connect an AC-device, I do get nice throughput. A Galaxy S 4 links at around 450Mbps and manages an actual throughput of around 225Mbps.

It's almost as if dualband (40MHz) isn't working on 5GHz wifi, but 20Mhz and 80Mhz are. I've tried a different firmware (latest Merlin bèta), but that didn't change a thing. Tried auto (20/40/80), tried forcing frequencies, tried disabling b/g protection etc....pretty much every setting there is I've tried. To no avail.

My testing setup is as follows
-AC66U linked up to notebook with gigabit ethernet.
-Have both the 2,4GHz and 5GHz on different ssid's, so I'm sure I'm using the right one.
-On the notebook I run iperf in server mode
-I then use iperf to connect from the clients and do a 30sec throughput test.

This is all done in a concrete basement where there are no other signals on the 2,5GHz or 5GHz frequencies.

I could really use some help. Is my router busted? I know I should be able to hit around 100Mbps with both the iPhone 5 and the Zenbook, but I just can't figure out why it's not working.

 

[woutf]

Still having this problem, it's driving me crazy. Can anyone help me?

 

[RMerlin]

55 Mbps out of your iPhone5's 150 Mbits link is normal. Throughput is never anywhere close to the link speed due to the overhead caused by encryption, amongst other things.

The 300 Mbits Zenbook should give you close to 100 Mbits, depending on how you test it. You could try a different channel at the opposite end of the range (if you were on a low-numbered channel then try a high-numbered channel, etc...). Some devices work better in one range or the other.

5 GHz should not be faster than 2.4 GHz unless using AC. 5 GHz is just the radio band used by the channels, 802.11n 40 MHz should be about the same speed on either the 2.4 or 5 GHz band.

 

[woutf]

55 Mbps out of your iPhone5's 150 Mbits link is normal. Throughput is never anywhere close to the link speed due to the overhead caused by encryption, amongst other things.

The 300 Mbits Zenbook should give you close to 100 Mbits, depending on how you test it. You could try a different channel at the opposite end of the range (if you were on a low-numbered channel then try a high-numbered channel, etc...). Some devices work better in one range or the other.

5 GHz should not be faster than 2.4 GHz unless using AC. 5 GHz is just the radio band used by the channels, 802.11n 40 MHz should be about the same speed on either the 2.4 or 5 GHz band.

Do you have any idea why some people (Anandtech in this example) are getting close to 100MBps on the iPhone 5?

 

[RMerlin]

Do you have any idea why some people (Anandtech in this example) are getting close to 100MBps on the iPhone 5?

I have a hard time believing they got 100 Mbps out of a 150 Mbps link, since a laptop with a 300 Mbps link gets around 120-150 Mbps on average.

 

[woutf]

I have a hard time believing they got 100 Mbps out of a 150 Mbps link, since a laptop with a 300 Mbps link gets around 120-150 Mbps on average.

Hmm, they've got quite the reputation for being thourough and reliable. But even if those numbers aren't correct, my Asus Zenbook Prime is also doing just 60MBps, even when the link speed is 300MBps. And the device is next to the router!

I'll try to fiddle around with the channels a little bit.

 

[RMerlin]

I couldn't find any methodology in their article. Nothing about what protocol/encryption was used, for instance. And these numbers don't match any of my personal real-life experience with a standard (meaning with WPA2-AES) setup.

 

[chrislazo86]

Woutf: Read more articles in the forum. Loom at 20mhz/40mhz channel bonding and theres an article here that will lead you through output speed and link speed difference.