FourHead: One PC, Four Users 496
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."
The heat! The heat! (Score:3, Insightful)
I would be interested to see how they handle it!
Re:The heat! The heat! (Score:2, Funny)
Since they are in Brazil, the easiest way would be to move to a colder country.
Re:The heat! The heat! (Score:5, Insightful)
As for the noise, it'll still be quieter than 4 separate boxes.
Re:The heat! The heat! (Score:2)
I don't think there's any reason it couldn't, if UT2004 had been designed for this. The thing is, I bet a lot of the CPU's effort when playing that is just tracking where everything is. You need to do that whether one person is playing or four. The actual rendering is done by the graphics card; so you've got four times the hardware there. So if you wanted t
Hate to burst your bubble... (Score:5, Insightful)
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:Hate to burst your bubble... (Score:3, Interesting)
Heat has never been an issue. And this is a standard ATX case - no mods, no heavy cooling. Just one intake, one exhast, and the PSU.
They're TNT2, and hardware GLX is supported... (Score:5, Informative)
Backtracking to Utah-GLX's driver (project page here [sourceforge.net], this will allow many complex openGL-phile programs to run at the same time given its architecture. I, however, doubt that older XFree86 3.3.6 will scale to this feat; I simply don't know. Yet, the Utah-GLX driver system has been ported to XFree86-4.x; it is a openGL GLX driver package in the form of dynamically loaded X Server modules/extensions and can be manipulated into and without the X Server without having to restart the X Server. It's somwhat parallel to the DRI driver, to provide an alternative, but it is not being maintaned anymore; Utah-GLX is dead and someone needs to commandeer!
I am using three Athlon Thunderbid 700MHz computers with a total 9 nVidia TNT2 adaptors total (three per computer), S-Video composite output to NTSC televisions, and quad-bonded 100BaseTX ZNYX LAN adaptors for verry low-latency threaded shared openGL rendering; I use as Chromium 3D videowalls, by using XFree86 4.3 and Utah-GLX's nVidia openGLX driver.
And yes, Quake3 looks hot!
OOOOH..... linguistic pet peeve (Score:4, Funny)
Drives me nuts every time someone says 'literally' to modify a phrase that it is literally impossible to construe in any way but figuratively.
~Sub
-1 Troll
-1 Flamebait
+1 Linguistic Merit
+1 Crankiness
Re:The heat! The heat! (Score:2)
barely any heat...
Re:The heat! The heat! (Score:2)
Just think about 3D intensive games, where both top notch CPUs and videocards are running on full load. It produces much more heat but it still can be handled. (Though the newer videocards are getting loud.)
Re:The heat! Probably not a problem.... (Score:3, Informative)
My machine has been running for a few weeks and is not noticeably hot, however they are not the latest state of the art graphics cards, esp
In Brazil? (Score:3, Funny)
Re:The heat! The heat! (Score:2)
Economy? (Score:2, Insightful)
Re:Economy? (Score:3, Informative)
Re:Economy? (Score:2)
Maybe this project is more a proof of concept? Somebody did produce cards which did this anyway with PS/2 connectors, VGA and even sound cards. This was a few years back, and you don't see them now PCs are so rediculously cheap.
Re:Economy? (Score:4, Insightful)
Also, boxes need replacing more often than monitors, so you get even more cost savings later on.
This is new? (Score:3, Insightful)
Re:This is new? (Score:2)
Seriously though, this is cool. It leverages the often unused computing power of workstations that are traditionally used as thin clients so that processing can be done. Definitely a cool project using cheap hardware and free software.
Re:This is new? (Score:3, Insightful)
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 wer
Re:This is new? (Score:3, Insightful)
Is it? My computer is running 3 right now... I use them to allow me to keep my work as one user while graphically logging in as another, or allowing others to login to the computer without me having to disturb my desktop environments.
Re:This is new? (Score:3, Insightful)
No it isn't. The first server listens at port 6000, the second server listens on port 6001, and so on. You specify which server to use with the DISPLAY variable (or the -display parameter) x.x.x.x:y.z where y is the server number. Multiple displays has been supported by X for a long time. Multiple input devices have been at bit less supported, but I guess that some of the CAD engineers early in the '90 have used it.
Virtual display
Re:This is new? (Score:5, Informative)
This has been done a long time ago... (Score:4, Informative)
http://cambuca.ldhs.cetuc.puc-rio.br/mult
But if one uses XGGI, its easy to get eight or more users on a single PC.
- A.C.
1975 called (Score:4, Funny)
1975 called. They want their computer headlines back.
Best regards,
Chairboy
Re:1975 called (Score:5, Funny)
Re:1975 called (Score:3, Funny)
(ob Seinfeld reference)
Re:1975 called (Score:2)
did they leave a message?
Re:1975 called (Score:2)
"You have 30 minutes to move your car"
"You have 10 minutes"
"Your car has been impounded"
"Your car has been crushed into a cube"
and finally:
"You have 30 minutes to move your cube".
2004 called (Score:2, Informative)
Well, you can [anandtech.com], but it's third party, very hardware specific [jetway.com.tw] and leaves you stuck with M$ XP. The Linux system demonstrated is a clear winner for schools, libraries, banks, casinos and other places where economical use of hardware is desired. While the Linux system might be difficult to maintain, it can be done. The Windoze solution leaves you dependent on the vendor. The people at Jetway have done an outstanding job but such is the world of proprietary software.
Anyon
Multi-headed Computer (Score:5, Interesting)
Also, you don't need 4 cards, You could do it with two. NVidia's twinview allows you to run two seperate X-servers off of one card (provided of course that it has two outputs).
Other problems (Score:2)
Also, you don't need 4 cards, You could do it with two. NVidia's twinview allows you to run
Re:Multi-headed Computer (Score:5, Interesting)
When I got a dualhead card, I knew that I wanted two separate desktops, between which I can switch with a hotkey, not by scrolling the mouse to the other display (I wanted to use virtual desktops on both). I was astounded that I could find absolutely no way of doing this, and no references to it on the Net.
The best I could do was make the screens separate and stop the mouse from going from the edge of one display to another, but then I found no way of moving the pointer to the other screen.
After a few months I found a suitable function call in the X libraries and wrote a small program, switchscreen [www.iki.fi], to switch between the displays. Now I've got two totally separate desktops between which I can move with a simple alt-tab.
You can read the details for configuring your X system like this in the README file included in the package.
Re:Multi-headed Computer (Score:3, Informative)
On multihead and Xinerama (Score:3, Interesting)
I use a standard (non-Xinerama) dual-head config and a dual-head aware window manager (Openbox 2.x). This setup has but one serious flaw, and that is the inability to move windows between the screens. What it offers over xinerama is that it does not require xinerama-aware applications. Popup notifications never show up in between the monitors, for example. The
Re:Multi-headed Computer (Score:2)
I think that is covered in the article, although I did not read through too much of the headache-inducing computer-translated Porgrish.
Yes, but with four cards, each with two outputs, you could have eight users! Although that would probably be too much use for all but email and word processing. You can probably do something similar with Matrox cards, I think they have a quad-output card or something crazy like that. Anyway, the dual-head cards are probably much more expensive than two low end single-head
Re:Multi-headed Computer (Score:3, Informative)
Ah, young Jedi, but there is a way...
Ruby, or Backstreet Ruby [tldp.org].
Note that this was in the article, though the link for Backstreet Ruby here [times.lv] is down - probably Slashdotted.
Beauty of open source.
Re:Multi-headed Computer (Score:3, Informative)
Nevertheless, it should be noted that Ruby needs to be grabbed from CVS, some instructions here [sourceforge.net]. Most of that is about the 2.4 backport, called backstreet ruby, but you'll get the 2.6 code along with it.
Translation (Score:2, Redundant)
My favorite line (Score:5, Funny)
Been there, done that (Score:4, Funny)
Hehe, it was good for playing tricks on my parents when they were sitting at the desk with the PS2 mouse and I'm sitting a few feet behind them with the handy wireless USB mouse.
*evillaugh*
Re:Been there, done that (Score:2, Funny)
>at the same time, and they could all control
>the cursor.
Plugging in a wireless mouse kinda defeats the purpose, don't you think?
Re:Been there, done that (Score:2)
This bit's talking about having four displays, four keyboards and four mice, where each mouce/keyboard pair controls a separate desktop/display. Completely different thing from just sticking a few more InputDevice-sections in the
Re:Been there, done that (Score:2)
Related question: anyone know if it's possible to set up something where you could have those mice be associated with different cursors (by color or shape) so more than one person can work at the same computer? I'm not talking about the article's described system, but between it and a typical computer. One display, multiple cursors.
(Each cursor can keep a separat
Been there, done that (Score:5, Funny)
Man, this is old news. We did this few years ago with five or more people on one machine. All we needed was a really small computer class, some free chairs, one PC, one keyboard, one mouse and one display.
Fastest (or strongest) got the best seats and the one with specs got the keyboard.
Talking about multi-tasking...
Are Dumb Terminals the new thin client? (Score:2)
Perhaps a method were PCs, ACT like dumb terminals. They are some kind of 'Resource' or extra limb of one 'Computer', running unix?
Might do a hell of a lot to improve security and administration in the long run.
Re:Are Dumb Terminals the new thin client? (Score:2)
Alternately you can have a small system installed on the machine itself (you could put it on
Re:Are Dumb Terminals the new thin client? (Score:2)
Re:Are Dumb Terminals the new thin client? (Score:2)
After twenty five years of computing, I'm starting to get real tired of people telling me what I am supposed to do.
Guide for something like this? (Score:2)
Warning - terrible joke follows... (Score:2, Funny)
(ba-dum-ching!)
(ducks impending flame doom)
Wow, lots of dumb responses... (Score:5, Informative)
'xterminals are cheaper' -- anyone care to back that up?
to:
'Windows terminal services can do this' -- don't know where to start on that one, suffice it to say: it can't.
to:
'This is just serial terminals' -- it isn't. RTFA.
I'm sure I missed a few...
Re:Wow, lots of dumb responses... (Score:2)
Slashdot needs new moderation options such as:
-1 Didn't RTFA.
-1 Don't be so negative.
The negative comments really bug me. There is a difference between being critical and dumping on someone's work.
ontopic: I had wanted to do this last year to share a home computer. At the time the needed patches were not stable enough. It is good to see that it works now.
Re:Wow, lots of dumb responses... (Score:4, Informative)
Sure
I buy NCD explora 701's and 402's all day long at $10.00 each the local community college was donated about 10,000 of the things and has no idea what to do with them. I have been buying lot's of 10 at $10.00 each and selling them to clients on the side. I also see them as well as the newer ones on ebay for around that price and up to $20.00 each. add a 15 inch monitor which can also be had for dirt (and has the EXACT same cost as this 4 head setup btw...) oh and keyboard, mouse. (same
I can add a workstation to a P-4 class server for around $75.00 each. that includes a new 15 inch monitor, mouse and keyboard + the ncd 701 terminal. each P-4 (1.2ghz) can handle about 10 users comfortably. and if you get 701 explora's or use old Pentium 233MMX machines, you get accelerated video playback (and most ALL xterminals support sound.) and seperate sound for EACH terminal... something that is not available on this 4 head setup.
the best way to actually set up a school full of x terminals is to have 3 servers... 1 for boot/ network management, 1 for 1/2 the apps and 1 for user login + storage and the rest of the apps.
using this setup we were able to install about 100 xterminals for a christian school for around $10,000.00US not including the wiring of the CAT-5e... that labor was donated by someone else.
so if you can show me that you can do it that cheaply (and yes, I make a profit at $75.00 each station... $39.00 each for gateway monitors, $10.00 each for the NCD terminals, $10.00 for cheap mouse and keyboard. that's $20.00 profit per station fro me) even at less than 100 units... my savings starts when the first pc is purchased. today's computers are horribly over-powered.
Re:Wow, lots of dumb responses... (Score:3, Informative)
Thinsoft sells BeTwin [thinsoftinc.com] which does exactly that. (The first versions were "PC Buddy" back in '99. On an ISA card, even!)
Of course it's more expensive (you need to buy software) than the Linux solution, but what Windows solution isn't?
Benefit? (Score:4, Insightful)
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.
Great gamer machine. No latency! (Score:5, Interesting)
Re:Great gamer machine. No latency! (Score:2, Insightful)
Re:Use some REAL hardware and you COULD do this (Score:3, Informative)
PCI-X is 4.3 GB/s (maximum!), and AGP 8X is 2.1 GB/s. Four graphics cards talking on a PCI-X bus would probably saturate it, especially given that it's shared-bus, so the number of bus arbitrations would be huge.
PCI-Express is point-to-point, so provided you could find a motherboard with 4 x16 links (good luck!) or at least had 4 x16 slots (again, good luck) you could do it.
But a 4 processor motherboard with 4
hey! (Score:2)
Diversity is good (Score:5, Interesting)
Re:Diversity is good (Score:2)
I think there is cynicism about this because it does not appear to be a scalable way of doing things; after all, there are only so many video cards you can plug into a PC, yet with dedicated X terminals, or even low-end PCs running X-servers, you could run a whole classroom off 1 reasonably specified Linux server. Managing that single server is probably going to be a lot simpler. With
Re:Diversity is good (Score:2)
But, yes, this is a good thing. I've been wishing I could do this at home, actually, because each PC means another heat source the A/C has to deal with.
What's curious... (Score:3, Informative)
And now Microsoft woke up.
After NEXT, GECOS and a couple others, PC has a GUI! Windows 1.0! Years after Amiga with real multitasking introduces Task Switching and later ('95) first Multitasking. Then the puny '98 "multi-user" (Amiga had that some 5 years earlier, UNIX machines way before that). And now, in 2004 we hear that after users of XP are tired of the pseudo-multisession of Switch User, SP2 is to include REAL MULTISESSIONING! Yeah, right! Two users can work on the same computer at the same time! Yay!
Noticed the catch? The keyword is "two". Yeah. Two sessions ought to be enough...
Stop The Presses (Score:2)
Oh. My. G0D.
And the reason this can't be done with Windows... (Score:4, Insightful)
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!!
60 users on 15 PC's - try 60 users on an 8MB VAX (Score:5, Interesting)
Has computing gone forwards or backwards when it takes thousands of times the compute power to support fewer users, doing dumber things. We used to run whole research departments developing mathematical modelling, computational physics programmes on a single DEC VAX 11/750 with 8 MB of main memory and like 80 MB of hard disk space. It was so underutilised that astrophysics would rent out time on the darn thing to geophysics and chemistry.
This was on 4.2 BSD, the mother of all open source operating systems. And we had access to supercomputers at Argonne, NCAR, LANL, LBL and Cornell over the ARPAnet. in the freaking early 1980's.
AND we produced beautifully typeset scholarly papers and theses, full of equations using TeX. Try doing that with Office. Hnf.
Personally, I used to use maple to do the algebraic manipulations, and export to either fortran (to run a numerical simulation to get the results that formed my thesis) or to TeX (in order to publish it). Sure as hell can't do that with the stupid Office (open or MS) programmes you need 15 64MB computers to support only 60 users on in this model. Even if you insist on running a pointy-clicky GUI, with X10 we used to run dozens of graphics terminals off of one VAX
This article just proves that the net progress of computing is actually backwards because the computers certainly are getting bigger/faster/better more slowly than the intelligence and creativity of the users -- now they all need a GUI just to edit text and compile programs. To the point that it's a miracle when you can have more than one person using a computer at a time now. Sheesh!
Re:60 users on 15 PC's - try 60 users on an 8MB VA (Score:3, Insightful)
This is a lot different than that - this is about taking an interface that has been designed assuming there is one user in front of it, and hacking it to support multiple users. M
Re:60 users on 15 PC's - try 60 users on an 8MB VA (Score:3, Informative)
Yes, but the X server was running on the terminals. The X apps running on the VAX only sent X primitives down the wire to the terminals, and the terminal bore the burdon of rendering stuff on the screen and processing kb/mouse input, turning them into events to send down the wire back to the app running on the VAX.
This article is about plugging the monitors/kbs/mices directly into the box
My first home computer (Score:3, Informative)
It had a Z80 CPU to handle I/O housekeeping chores and an MC68000 main CPU running XENIX (a flavor of UNIX).
It supported four users at the same time - each at their own terminal - with no additional goodies needed at the 16B+.
Mine did have a full load of memory, a larger hard drive, and a few Hayes modems so the other users could be remote, but the modems hooked right into the existing multiple ports on the machine.
For several years it was a minor mail and news server on the web (named tijil).
In what major way it this "new" thing astonishingly different from what I had 20 years ago on my desktop at home?
Take care,
Tomas
Re:Hello and welcome to last week (Score:2, Insightful)
Re:Hello and welcome to last week (Score:2)
Microsoft has TS clients for even Win 3.1.
Re:Pardon my ignorance (Score:2)
Re:Pardon my ignorance (Score:2)
Re:Pardon my ignorance (Score:2)
Er, wait. Is this a joke, or did you just not RTFA? Go read the article- there's a picture. It has nothing to do with splitting one monitor into quarters.
Re:Mainframe? (Score:5, Funny)
Re:Mainframe? (Score:5, Informative)
This is a standard computer handling several video outputs, keyboards and mice by itself. Just the same as any one person system, but handling multiple persons instead.
Or something.
Re:Mainframe? (Score:2, Insightful)
Not always. The IBM 3270 architecture (I think it had another name as well) could use graphics terminals with high resolution rendering, mouse etc. Quite a bit of local processing could be done.
Actually just a monitor, mouse and keyboard would have to rate as a dumb terminal. Even acsii terminals had some intelligence for cursor positioning etc.
Re:Mainframe? (Score:5, Interesting)
and has way more overhead and cost than using old P-I233 computers or dirt cheap x terminals on a network.
I can support 10 users on one machine using Linux Terminal server for 1/4th the cost of their supporting 4 people on one machine.
and I have a overall lower processor load.
It's neat, but nothing more than that right now.
Until the supply of free Pentium I class laptops and desktops dry up or the sources for dirt cheap xterminals dry up, it's nothing more than a expensive wy of doing things.
Re:Mainframe? (Score:2)
it does workstation stuff very well (Score:4, Insightful)
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.
Re:it does workstation stuff very well (Score:3, Insightful)
Which is why we moved away from the mainframe in the first place.
The benefit of this technology, if there is one, is that four users with bare minimum needs can share one commodity computer. Control four web terminals at your coffee house from a si
Re:it does workstation stuff very well (Score:3, Insightful)
That simplifies the explanation though.
You might go to 2x or 1.5x instead. The end
result is still faster most of the time, because
the PC spends nearly every moment being idle.
My load average is 0.14 right now, and I'm not
even using a modern system. (old 450 MHz Mac)
Despite the low usage, there are times when I
must wait.
With the 4-user box, you also save on electrical
power, noise, air conditioning, and physical space.
Re:Mainframe? (Score:5, Informative)
Do a bit more research, and you find that those mainframe installations had processors that ran at clock rates somewhere between 1 and 20 MHz, with typically a few megabytes (equivalent) of RAM, and a few hundred megabytes of hard disk. (And a few tape drives, but the tapes were not really used that much, by comparison.)
As a convenient example, consider the Control Data 6600 supercomputer at UT Austin in 1970. The CPU clock was 10 MHz, and it had just 131,072 words of main core memory, at 60 bits/word (which works out to about 1 Megabyte). It had two disk subsystems, one of which stored 168 million characters, the other storing 241 million characters.
Compare this with a 486/33, with 4 megabytes of RAM, a 200 Mb and a 340 Mb hard drive. 4 times as much RAM, probably comparable CPU throughput (the 6600 CPU was a master of parallel execution: it could be running as many as 10 instructions simultaneously).
The 6600 was heavily time-shared.
Late in the 1970s, things started getting interesting. The magic point was called "3M", which stood for "1 MIP, 1 Megabyte, 1 million pixels", and the price on that was JUST BARELY within reach of an individual.
Now look today. Our LOW END personal computers come with HUNDREDS of megabytes of RAM, hundreds of MIPS, tens or hundreds of gigabytes of disk storage, and several million pixels. (The limit on pixels is what you can get onto a display and refresh at a reasonable rate.)
What limited these guys to "only" four users per PC wasn't processing power or video bandwidth. It was the number of PCI video cards they could physically stuff into a PC motherboard.
Re:Huh!? (Score:2)
1 cpu and mobo, 4 graphics cards, 4 sets of kb/mice.
there's a commercial solution to do this in windows as well iirc, but just for 2 screens..
Re:Huh!? (Score:2)
To ask the question yet again, so what? The only thing different with this is that you have bus connections instead of network connections, allowing dumber terminals than normal. But really, so what?
X terminals never caught on in the PC world, but there's no reason someone couldn't start manufacturing $100 i486-based X terminals. Absent that, just go grab any "obsolete" PC and slap Linux/BSD on it and you have an in
Re:Huh!? (Score:2)
This solution uses standard computer peripherals for the "heads"( I/O ) and a standard video card to drive the display. The single GNU/LinuxPC is used to drive/power the 4 "heads" computing resources.
The difference here is also that fact that the "heads" must be local to the computing chasis. With X-Terminals, the "heads" can be anyw
Re:Privacy issue? (Score:2)
Re:Privacy issue? (Score:5, Informative)
I suggest 4 CD-ROM drives and correct permissions set in fstab so everyone can use -their own- drive only
Re:Privacy issue? (Score:3, Funny)
Re:Awesome: But Easier Way? (Score:2)
Re:I disagree (Score:2)
We are far past this era.
Heard about VT100, diskless workstations, glass tty, do you know what "mainframe" meant originally?
They are were replaced with "individual boxes" because hardware got cheaper and setting this all up to work correctly costs a lot of effort.
(try to set up a diskless network-bootable linux box and you'll see what I mean)
Re:I disagree (Score:2, Funny)
Re:LTSP still a better option (Score:4, Insightful)
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.
Re:LTSP still a better option (Score:2)
Re:4??? (Score:2)
Re:Why is this newsworthy? (Score:2)
Bedlam (Score:2)
Re:I can't believe I'm reading this on /. in 2004 (Score:2)
A GeForce2 video card costs $30-$40.
A PC capable to serving as an X terminal costs $200-$300.
(yes, these are new prices, if you're using used equipment for the X terminals you have to match that with used equipment for the multi-user box as well)
Re:I've wanted to do this with windows... (Score:3, Interesting)
In fact, we installed 10 workstations using this system on 5 PCs for a client of ours recently--replacing 10 old iMacs--to lower the TCO for a small call center.
It's been working great, no problems whatsoever.