FourHead: One PC, Four Users

LoganGD writes "A reseach group from UFPR university in Brazil, C3SL has managed to make one Linux box run four terminals at the same time. That means four mice, keyboards, displays and users with just one CPU. The way they managed to do that can be found at the FourHead project webpage. The fact that one computer science laboratory can suport up to 60 users whit only 15 PCs is really attractive for low-resource groups and countries."

Comments

This is new?

[Aero Leviathan]

Wasn't this what Unix (and/or its predecessor, Multics) was designed for?

Re:This is new?

[Anonymous Coward]

Nope this is not new at all.

However running multiple instances of X on a single computer is pretty new. Before you had seperate machines that acted as X terminals that had their own low-power proccessor and video card for driving the gui and their own keyboard and mouse. Then those plugged in thru the network and into the computer that way.

With this method you simply attatch the monitors and keyboards to a single machine and share the resources that way.

More direct and a bigger pain in the arse. PC's were disigned for single user only, putting multiple keyboards and mice and assigning them to specific users is quite a hack. To most people they have old PC's laying around that make great X terms without having to go thru that effort.

X terminals is the way to go in office and especially school enviroments. You have a single computer serve multiple people so it may seem that is going to be slow, but realise that the majority of the time the CPU is near-idle most of the time on a single machine. Also by investing in higher performing disks like scsi array you can even increase performance because it's cheaper to do that then buy a have dozen new machines with a single low end IDE harddrive on it.

Also you remove the need for complex network setups like Active directory. It's much more secure and easier to simply setup a multiuser setup on a single Linux machine. It's already setu p like that by default, and X terminals is a nice extension on that.

Centralize administration, make backup easiers. Reduce network problems, reuse obsolete PCs without pissing anybody off, higher reliability, higher disk performance, cheaper. etc etc etc.

By centralizing your reasources you can spend big bucks on a few fast machines, then spreading them out on error prone low-end machines that require a lot of admin time to upkeep.

Re:The heat! The heat!

[Arathrael]

It's not like the graphics cards are going to be pushed to the limit - I mean, the CPU wouldn't cope with them all playing ut2004 at the same time. :-) So they shouldn't be generating all that much heat, couple of case fans should cope with it no problems.

As for the noise, it'll still be quieter than 4 separate boxes.

Hate to burst your bubble...

[Anonymous Coward]

But not everyone runs top of the line NVIDIA cards. I imagine the cards in this box are probably low budget Geforce 2's. Probably MX 200's. Might even be lower cards then that, since why do they need hardware 3d?

I don't think anyone could argue that these create massive amounts of heat. What heat they do create can easily be exhausted by a case fan.

This is definitely a setup for an environment where people are literally running on a shoestring budget. This is a really nice ability, and I'm glad someone has done it.

Re:Economy?

[Texas Rose on Lava L]

These guys aren't using 21-inch flat panel monitors. A 17-inch monitor costs around $100 or so. Mice, keyboards, etc. are cheap. If the boxes are $300, plus $150 for a monitor, keyboard, and mouse, they're reducing the cost of 4 computers from $1800 to $900. This would mean they could support twice as many users without increasing the budget.

Also, boxes need replacing more often than monitors, so you get even more cost savings later on.

Benefit?

[div_2n]

Ok, so by the time you spend all of the time and effort to do all of this, you could deploy a fully self contained thin client in what, 10 minutes?

The only way I see this as a good idea for any low budget organization is if they get donated lots and lots of monitors, keyboards, mice and computers with graphics cards for this project.

Re:LTSP still a better option

[tempmpi]

TCO depends a lot on wages vs. hardware/software costs. If the wages are high, it can make sense to spend more money on hardware/software if that causes less downtime and less work for the adminstration. But if the wages are low, work-intensive solutions with slightly more downtime can become acceptable and have a lower TCO in the end. In countries like brazil I wouldn't be so sure if the TCO of a LTSP is really lower.
Not unlikely hardware is more expensive than in the US and the wages are a lot lower for sure. And students are working on these PCs, so downtime is almost free. I believe such a four head solution also provides better response than a LTSP installation. Video playback and similiar stuff should be possible on a four head installation.

it does workstation stuff very well

[r00t]

Most of the time, your PC sits idle while it waits
for you. Every now and then, you sit idle while you
wait for the PC.

Now get a 4x faster PC, and share it 4 ways.
Very seldom will all 4 users need the CPU at once.
So, nearly all of the time, you'll get better
performance. When you need the CPU, most likely
the other 3 users are reading, thinking, chatting,
drinking, picking their nose, or whatever. The
fast hardware is all yours.

And the reason this can't be done with Windows...

[NoMoreNicksLeft]

Could it be that windows doesn't support multiple monitors? No.

Or that it can't support 4 different users on them (as opposed to 1 user getting a big display)? Probably not, at the very least, it would be hackable.

Maybe it can't support multiple keyboards, or mice? Again, the most it would need is some hacking.

Or maybe, just maybe, if you posted a webpage, telling someone how to use a single windows license for 4 users, M$ legal would go apeshit on you, and stomp you into a tiny, tiny greasestain?
BINGO!!