USB 3.0 Impact on 2.4Ghz Wifi is Real

[Roy2001]

The day before when I did site survey, and was surprised to find out that all my neighbor's router were gone, I thought it was due to bad weather. After 3 days router still sees nothing but 3 weak 5Ghz AP's.

I am living in a house, I can see about 10 weak 2.4Ghz AP's with signal strength around 10%, but they are all gone.

Today I just recall that recently I connected a USB HDD to USB 3.0 port on AC68U. So I unplugged it, and all my neighbor's 2.4Ghz AP's are coming back as usual. So the the USB3.0 cable would impact the 2.4Ghz wifi signal even it is not reading/writing files. I did not test the quality or speed with USB 3.0 plugged in, but I guess it would be a problem if I am far enough from router.

I also tried USB 3.0 flash drive and it is not a problem. So according to this paper, it is expected:

http://www.intel.com/content/www/us...al-bus/usb3-frequency-interference-paper.html

 

[sfx2000]

The interference for USB3 is usually near field - and this can impact 2.4GHz on the Router/AP itself esp. if one is running poor quality cables...

It's a broad spectrum noise source, and typically will impact channels 6 thru 11 (and thru 13 in regions that allow those channels)

 

[snakebite3]

The interference for USB3 is usually near field - and this can impact 2.4GHz on the Router/AP itself esp. if one is running poor quality cables...

It's a broad spectrum noise source, and typically will impact channels 6 thru 11 (and thru 13 in regions that allow those channels)

What's good USB 3 cable? I bought a 6FT triplelit and tried moving the USB drive as far away from router as possible but it didn't make a difference. I didn't get over 30MB reads. I OC the router too. I was expecting 40MB. I got 90MB with the flash drive and cable on my PC.
This what I got.
http://www.newegg.com/Product/Product.aspx?Item=N82E16812228003
I got because it empathize on Premium Shielding.
"Premium double-shielding cables with tinned copper braid and aluminum Mylar foil minimize signal interference. Molded connectors and integral strain relief assure durability and long cable life. A flexible PVC jacket makes the U324-006 easy to install, even in tight corners and other areas where space is restricted."

 

[Roy2001]

What's good USB 3 cable? I bought a 6FT triplelit and tried moving the USB drive as far away from router as possible but it didn't make a difference. I didn't get over 30MB reads. I OC the router too. I was expecting 40MB. I got 90MB with the flash drive and cable on my PC.
This what I got.
http://www.newegg.com/Product/Product.aspx?Item=N82E16812228003
I got because it empathize on Premium Shielding.
"Premium double-shielding cables with tinned copper braid and aluminum Mylar foil minimize signal interference. Molded connectors and integral strain relief assure durability and long cable life. A flexible PVC jacket makes the U324-006 easy to install, even in tight corners and other areas where space is restricted."

USB 3.0 read/write speed is limited by SoC speed, so 1.4Ghz is faster than 800Mhz. The impact is 2.4Ghz signal strength, not USB read/write speed.

 

[snakebite3]

USB 3.0 read/write speed is limited by SoC speed, so 1.4Ghz is faster than 800Mhz. The impact is 2.4Ghz signal strength, not USB read/write speed.

I understand that. The signal strength is affect with the cable too. Just disabling USB 3.0 interfering reduction with nothing plugged in will do that. I got the impression using a quality cable will prevent that.

 

[Roy2001]

I understand that. The signal strength is affect with the cable too. Just disabling USB 3.0 interfering reduction with nothing plugged in will do that. I got the impression using a quality cable will prevent that.

If you need speed bump, try to overclock the SoC.

 

[snakebite3]

If you need speed bump, try to overclock the SoC.

It is overclocked. I was using 1200 before. It's currently at 1000.
For some reason Asus latest router have crappy USB 3 speed too. It advertise 100MB but it doesn't get close to that.

 

[wocram]

It is overclocked. I was using 1200 before. It's currently at 1000.
For some reason Asus latest router have crappy USB 3 speed too. It advertise 100MB but it doesn't get close to that.

You should also try another drive to see if it makes a difference.
With my flash drive, I also get a max speed of 15-20MB/s.
When I however connect a 2TB WD mechanical drive, I get download speeds between 50 and 60 MB/s!

 

[sfx2000]

What's good USB 3 cable?

Most of the OE cables provided with external drives are good enough, as the drive vendors are aware of the challenges here...

I do worry a bit about some of the "high end" stuff sold - as who certifies this - easy enough to put a label on things - the most common thing I've found is shielding not connected to the connector itself...

There's a whole 'nother issue with third party USB-C cables at the moment - many of those are non-compliant...

USB/USB2 was easy enough - when we get to USB3, everything changed - from cables to hubs...

 

[Cake]

I thought I remember the ac68u had a problem with that. A revision later and they beefed up the USB cable to the board to stop interference and slow speeds.

 

[nephilim]

I thought I remember the ac68u had a problem with that. A revision later and they beefed up the USB cable to the board to stop interference and slow speeds.

Could you please clarify what "a revision later" means? B following A or A2 following A1