3

I bought the following product to get good internet in my room: AWUS036ACH 802.11ac AC1200 Wide Range USB 3.0 Wireless Adapter with External Antenna

I'm planning to buy a Pi 3 to use this wireless receiver with. Because of the distance from the router my internet connection's speed is max 40 Mb/s.
I'm wondering if a Pi 3 will be able to coupe with this speed put it in the following setup:

router
-wifi->
AWUS036ACH
-USB->
Pi 3
-ethernet->
Apple Airport
-wifi->
my computers

If Pi 3 has 10/100 Ethernet I can assume max. 100Mbps/8=12,5 MBps theoretically. My internet connection gives max 40Mbps/8=5MBps, so I can expect Pi 3 to couple with the speed in practice.(btw I know ratio 100/40=12,5/5). But from what I read a Pi 3 uses the same controller for ethernet and USB. That's why I don't know how to estimate the speed it will get. Can I expect the controller to run at full USB 2.0 and 100 ethernet speed at the same time?

Also another related issue: I have no clue whether the latest version of raspbian jessie using kernel 4.4 will support my USB receiver AWUS036ACH. It has a Realtek RTL8812AU chipset. Can someone please explain me how I can find it out without having to buy a Raspberry Pi 3 first (student budget here)?
I was planning to connect AWUS036ACH to an emulated raspbian, but I guess qemu can't redirect hardware to the virtual machine like e.g. parallels do. Anyways, yesterday I tried to emulate jessie raspbian the whole day, but had no luck finding the right kernel to use with the latest image you can download from raspbian.org (not in the mood to compile a whole OS). Someone should release a pre-packaged 4.4 kernel + img with jessie. I could only find pre-packaged images for qemu with old kernels and OS.

  • Given you have two streams of data going through one controller definitely do not expect to get full USB 2.0 or 100 Ethernet speeds from your Pi. – Darth Vader Sep 25 '16 at 14:06
2

Can I expect the controller to run at full USB 2.0 and 100 ethernet speed at the same time?

No, the total bus speed of everything combined is limited to 280 Mbps. This is in theory enough if you are passing 40 Mbps through from USB to ethernet.

It has a Realtek RTL8812AU chipset.

This one isn't explicitly referenced in the vanilla kernel source driver tree, and while there may be one available, this is not a simple or guaranteed thing to do on a Pi.

  • Thank you very much for your answer. I'd up vote it if I could. – Yuri Borges Sep 25 '16 at 14:03
  • You can tick the big checkmark stage left if you are satisfied with this as the answer. You may want to wait and see on the chance that someone who's used that adapter comes along, but I wouldn't hold your breath. – goldilocks Sep 25 '16 at 14:04
  • Also I just found a link to the driver for raspbian in the manufacturers' news blog. It's so weird they are recommending a driver compiled but some random guy on GitHub... – Yuri Borges Sep 25 '16 at 14:07
  • Realtek don't really support linux; although I think they've put out some drivers of their own, they won't open source them which makes it impossible to match them to kernels, which are usually being updated regularly. It also makes it impossible to compile them for odd platforms such as the pi. So it is up to other people to reverse engineer them, which is tedious and prone to problems. It may not be impossible, but again, there's no guarantee and it leaves you with the hassle of compiling it yourself, which in the long run is probably not worthwhile vs. $15 for a known working adapter. – goldilocks Sep 25 '16 at 14:29
  • 1
    I would avoid any realtek wifi products; between the lesser too evils in the cheap field, I would go with broadcom. Atheros is the best choice for linux, ralink comes next and it it cheaper – Rui F Ribeiro Sep 26 '16 at 2:23
1

If, IF you have a managed switch, that you can force the Cat5e - Cat6 - Cat6+ port to 100 full duplex. Now the quality of your patch cables and your infrastructure must be Cat6 or higher. You can not use your own build cables. Not even the ones they sell at online retailers. High quality is the ONLY way you get great throughput. I've run a terminated and tested Cat6, as high as 9db. That's amazing! Math has nothing to do with a bad connection or patch cable. IDK if you can push the Pi Ethernet to Full Duplex or not? I'm running off a dumb switch. The HP 108 is the smallest manageable layer 3 switch, I have one in my backbone. You have to have cables from professional suppliers. Never homemade! Twists of each set of pairs are engineered to a specific length. This diminishes/eliminates cross-talk between pairs, based on the sinewave of each signal.

  • Careful, the poster didn't ask for product recommendations. Suggesting brands and suppliers could get you a spam flag. – Dmitry Grigoryev Sep 26 '16 at 13:29
  • Fixed, thank you! – Joel Huebner Apr 1 at 5:34

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