Pogoplug Series 4 USB Bus capacity better than E02's?

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Pogoplug Series 4 USB Bus capacity better than E02's?

Postby permitivity » Wed Sep 25, 2013 4:41 am

Has anyone tried to use two USB webcams on a Pogoplug Series 4?

I have experience with E02's and I've never been able to get two USB webcams on it. One always fails to produce any image, and I think it's a USB bandwidth issue.

I know Pogoplug Series 4's have less ram and slower CPU clock speed, but that might be fine for certain applications. Like if you want to run Motion with two webcams. You don't need all that much RAM or CPU power for Motion. The Series 4 seems to have a different bus structure, it's not just adapting SATA and USB3 to existing hardware.

This pogoplug enthusiast (40-something geek blog) guesses that the Series 4's slower than expected transfer speed is due to CPU bottleneck, not bus limitation.

http://fortysomethinggeek.blogspot.com/ ... eview.html

Just wondering if anyone here has a Series 4 and has direct experience.
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Re: Pogoplug Series 4 USB Bus capacity better than E02's?

Postby WarheadsSE » Wed Sep 25, 2013 3:46 pm

CPU & Bus speeds are slower. The USB3 is attached via PCIe, but still hits a slower bus @ the CPU.
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Re: Pogoplug Series 4 USB Bus capacity better than E02's?

Postby digitlman » Tue Dec 10, 2013 9:17 am

$this->bbcode_second_pass_quote('permitivity', 'H')as anyone tried to use two USB webcams on a Pogoplug Series 4?


Yes, and successfully (using Logitech HD webcams). With my Pink Pogoplug v2 (B02), I could only get one HD webcam and one VGA webcam working concurrently (using mjpg-streamer and v4l2). I've been using this setup a cheap IP security camera solution for over a year now (with a Microsoft LifeCam Studio at 1280x720 and an Xbox Live Vision camera at 640x480).

With the Pogoplug v4, I was able to get 2 HD webcams (Logitech) working concurrently at 1280x720 resolution (using the 2 USB 3.0 ports), and the whole process was much easier than with the old v2 and the deprecated kernel. I tried different combinations of Logitech C615 and C930e and all worked, but when I added a Microsoft LifeCam Studio to one of the ports, I no longer could run 2 concurrent cameras at 720 resolution. I assume this is because the Microsoft cams just don't support the same UVC compression modes that the Logitechs do, so it ends up using YUV/BGR (uncompressed) encoding and using up too much of the USB controller's bandwidth. I don't think the issue is CPU utilization. I had a hard time getting even a single LifeCam Studio to work reliably with the Pogoplug v4, so I just wouldn't recommend it. I do like the Microsoft webcams for their extended focal range, but they don't seem to work with with my Pogoplug v4.

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