Making A Easy-To-Setup $50 Linux Multi-Seat Computer

[bernieplugable]

For now, USB 2 will give better results anyway

I would like to see if USB 3 would improve this. I can see it being really useful, even for just families.

We do think families will like this kind of solution (assuming the kids are happy in Linux or the browser). I've run (an older USB multiseat solution) my own house for months at a time, and it's great to have only one computer to maintain. The only tension is all the old Windows game CDs we have laying around that Wine wouldn't run.

In terms of USB, Michael mentions the key problem -- but even on top of that, there are practical issues that mean USB 2.0 is a better overall solution in almost all cases today. USB 3.0 devices and infrastructure cost more. But the biggest issues are USB 3.0 cable length and stability. USB 2.0 is great in that there are cheap cable available providing long runs with no errors (we sell a 10 meter active cable like this). Whereas USB 3.0 is dodgy even beyond 1 meter. Also, it's great plugging lots of thin clients into a single 7 or 10 port USB hub. With USB 3.0, only 4 port hubs are out now (and the quality of them varies greatly). You want a setup like this to be rock solid (and with USB 2.0, it can be with good hardware).

So we expect USB 3.0 solutions to make their way onto the market, but actually USB 2.0 has a whole bunch of benefits (even given the constrained throughput). Remember that only the pixels that are changing are going over the bus (and compressed, at that). So it's actually surprising how performant the USB 2.0 solutions are.

Hopefully Michael will have the chance to do some more benchmarks and videos in his own lab, showing the full performance story. It's not for gaming or 1080p motion video, but it's great for information work and good enough for Youtube-quality video. That's not for everyone, but it meets many needs, especially at schools and non-profits.

I hope we get a few people here interested enough, to give it a try and see it in action. Thanks for posting!

[schmidtbag]

SINCE WHEN do call-center operators need graphics acceleration on their workstations? These setups are GREAT for petition drives etc.

WHO NEEDS ACCELERATED GRAPHICS FOR DATA ENTRY? OMFG! 15 years ago we did this with monochrome Sun3 displays AND THEY WERE OVERKILL.

Hey why not some MORE hyperbole! Oh my God how can you POSSIBLY sit in front of a display with less than a zillion terabits of display bandwidth! I mean REALLY it's just IMPOSSIBLE to even LOOK at a screen if it can't update EVERY pixel for EVERY frame!

lol looks like somebody woke up on the wrong side of the bed this morning, and that side of the bed happened to have a concentrated energy drink.

But anyways, I see what you mean but for some cases hardware acceleration is needed. Yes, if all you are doing is typing a document then you don't need anything better, but if you are doing something like web browsing (which places like schools and libraries would often have) then no hardware acceleration takes a BIG hit, big enough to the point that other users would be directly affected.


As for anybody using a multi-seat setup where most of the seats aren't accelerated, I'd recommend looking into VirtualGL, which allows you to port GPU processing power over a network, which in turn allows you to get hardware acceleration on an otherwise unsupported platform. The nifty thing about it is you could use a real powerhouse of a GPU on a crappy netbook, or a virtual machine.

[frantaylor]

Always???

The lack of graphics acceleration in thin-client-like multiseat solutions has always been a put-off. .

SINCE WHEN do call-center operators need graphics acceleration on their workstations? These setups are GREAT for petition drives etc.

WHO NEEDS ACCELERATED GRAPHICS FOR DATA ENTRY? OMFG! 15 years ago we did this with monochrome Sun3 displays AND THEY WERE OVERKILL.

Hey why not some MORE hyperbole! Oh my God how can you POSSIBLY sit in front of a display with less than a zillion terabits of display bandwidth! I mean REALLY it's just IMPOSSIBLE to even LOOK at a screen if it can't update EVERY pixel for EVERY frame!

Really, people who program computers can blithely stick "ALWAYS" into their communications with humans and they don't expect to get it thrown back at them?

[PeterKraus]

Interesting. I wanted to get a multiseat solution a year ago, when I used to have my office sharing a wall with the living room. I would have just used standard VGA connection and maybe an USB hub for the keyboard / mouse.

Though, considering the points some people made in this thread, the USB 2.0 might not be the right choice. I was wondering if Firewire (with DMA) or USB3.0 wouldn't have been better.

On the other hand, I would be interested in seeing that software part. Configuring (persistently) the new seat seems to be the biggest issue with the current state of multiseat, and also you need a graphics card head for each seat - that's where that onboard GPU comes in handy. Then, the only limitation becomes the length of your VGA/DVI cable....

Here's a great howto, by the way: https://wiki.archlinux.org/index.php/Xorg_multiseat

[TdR91]

Hey i want to play open source source engine games on 5 terminals with open source drivers and wayland!
Just kidding... It looks like interesting stuff.

[pingufunkybeat]

For $150 you can have an E-350 AIO system that would run circles around this

For $30, you can have another gfx card, and then you can have fully accelerated multi-seat with 3d and desktop effects on each seat. That's what I'm running at home right now, and other than modifying a kdmrc and xorg.conf I found on the internet, it was quite painless to set up.

It's only when you get past 4 seats that this approach starts having problems, because you need a better motherboard, better cooling, etc.

The plug and play aspect of this is nice and appealing, but seriously, multi-seat is relatively easy for a moderately experienced Linux user, and all you need is an extra gfx card (the weakest one will do). Hopefully, in the future, you'll be able to run multiple seats off one card, with that patchset agdf had floating around...

[Michael]

I would like to see if USB 3 would improve this. I can see it being really useful, even for just families.

I talked about it with Bernie when at their office. DisplayLink does have a USB3 chip now, except there's currently no Linux support.

[fuzz]

I would like to see if USB 3 would improve this. I can see it being really useful, even for just families.

[GreatEmerald]

In the video, he refers it to as "lowering cost of computing", but it doesn't lower the cost of computing.

He also refers to it as a computer even though it isn't a computer.

He says it reduces the cost of computing to $50 per user, but it doesn't, because it needs a computer, mouse and the screen so the real TCO is significiantly higher.

This should be better directed at the article title... Now it feels like it's a full computer capable of multi-seat for $50, while it's actually an USB hub on steroids for $50.

Regardless, it's definitely interesting. One thing's for certain, very often there is unneeded power in PCs that could be used by someone else. This could be very useful in libraries, schools and workplaces, where the environment is rather strictly managed yet needs to cut the cots as much as possible while having it easy to maintain. Overall this centralised computing model is very useful when there is some extra expenditure involved in the software side, as for one license, the whole workplace is able to access the software, therefore further cutting costs. Not that it's all that relevant to OSS, though, usually you don't need to pay any extra for that at all.

The kickstarter options are pretty nice, too. I'm not a fan of options like "give $25 and receive a T-shirt!!", whereas these ones are actually meaningful.

[locovaca]

The resolution is limited to that because that's all the DisplayLink hardware can probably handle. I have two DL devices (EVGA branded) that can only go max at 1680x1050. I might add that they are slow for anything other than largely static content, since they're only USB 2.0. They also can tax the CPU while trying to view dynamic or moving content because the CPU is compressing the images down to minimize the amount of data sent across USB. Also, the performance decreases for each device you add since USB 2 is a shared bus and the bandwidth is split across all devices on that bus.

For $150 you can have an E-350 AIO system that would run circles around this, and wouldn't be tied to another computer. You could probably find used Atom 330 AIO systems used on eBay for even cheaper.