vbman213
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Wi-Fi performance varies between two identical raspi3?

Sun Apr 24, 2016 5:10 pm

Two new Raspberry Pi 3s (left and right):

Code: Select all

http://i.imgur.com/6gJJ0dC.jpg
Both running identical software.

iPerf3 test (left):

Image

iPerf3 test (right):

Image

What could be causing such a sharp difference in performance? Both Pi3s are associated with the same access point, in the same physical location.

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mikronauts
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Re: Wi-Fi performance varies between two identical raspi3?

Sun Apr 24, 2016 7:24 pm

Disable power management for the Pi3 on the right - I've seen this issue discussed in the forum.
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Advanced Robotics, I/O expansion and prototyping boards for the Raspberry Pi

vbman213
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Re: Wi-Fi performance varies between two identical raspi3?

Sun Apr 24, 2016 8:02 pm

As have I, but what differences between these two identical Pi's (same hardware and same software) would cause such a sharp contrast in performance?

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FTrevorGowen
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Re: Wi-Fi performance varies between two identical raspi3?

Sun Apr 24, 2016 8:36 pm

vbman213 wrote:As have I, but what differences between these two identical Pi's (same hardware and same software) would cause such a sharp contrast in performance?
Just to confirm the situation - are you literally using the same (external) hardware and software ie. uSDHC card, power supply, cables etc. and just swapping the Pis? (Power supply and/or uUSB power cable differences could contribute)
Trev.
Still running Raspbian Jessie on some older Pi's (an A, B1, B2, B+, P2B, 3xP0, P0W) but Stretch on my 2xP3A+, P3B+, P3B, B+, A+ and a B2. See: https://www.cpmspectrepi.uk/raspberry_pi/raspiidx.htm

drgeoff
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Re: Wi-Fi performance varies between two identical raspi3?

Sun Apr 24, 2016 9:32 pm

If the photo is of the actual setup giving the different measurements, the first thing I would do is to move that huge paperclip away. Its size is comparable with half a wavelength of 2.4GHz and could be affecting field strengths differently depending on the direction to the Access Point.

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Dis93
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Re: Wi-Fi performance varies between two identical raspi3?

Sun Apr 24, 2016 9:48 pm

Image
meta

vbman213
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Re: Wi-Fi performance varies between two identical raspi3?

Sun Apr 24, 2016 9:55 pm

FTrevorGowen wrote:
vbman213 wrote:As have I, but what differences between these two identical Pi's (same hardware and same software) would cause such a sharp contrast in performance?
Just to confirm the situation - are you literally using the same (external) hardware and software ie. uSDHC card, power supply, cables etc. and just swapping the Pis? (Power supply and/or uUSB power cable differences could contribute)
Trev.
Yes. Same PSU, power cable, HDMI->DVI, and monitor. The only thing that is different is the Pi3 board itself.

I will move the paperclip...

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