How is desktop formed?

December 23, 2007 4:49 PM

How is desktop formed? How do icons get on scraen?

But seriously, folks. I've got an older PC that I've been stripping down, trying to reduce its heat and noise levels. I'm removing anything I don't need to perform a couple specialized applications.

So. In a normal PC setup, the desktop data (names and locations of icons, color settings, all that) is generated by the processor itself and output to the video card, which generates a VGA signal and sends it to the monitor and I see the visual representation of the logical desktop. Right so far?

The machine in question isn't hooked up to a monitor right now. It's connected to my network via wi-fi, and when I want to talk to it I do so via VNC from my laptop. I get a window and in that window is what looks just like the desktop I used to get on a monitor via a video card.

So here's my question. Under that scenario, is the video card actually doing anything? What I'm ultimately asking is, if this is the only way I plan to interact with that machine from now on, can I just pull the video card completely and run without one? Or will there be no desktop without it? Will it freak out Windows in some way, or cause other unforeseen problems? (Sorry if this is a really dumb question but I've never come across this idea before.)

posted by Naberius to computers & internet (15 comments total)

Does the system in question have integrated video on the motherboard? If it does it'll certainly run if you pull the card. If it doesn't it probably won't, though some motherboards have BIOS settings that will allow you to set the video card to "none" and run as a truly headless system. Usually only found on server-level systems.
posted by aerotive at 5:02 PM on December 23, 2007

It's called a headless machine, and being able to do it or not depends on the motherboard. Professional server-grade motherboard? Likely so. Consumer grade desktop motherboard? What you'll likely get is a POST error, which will consist of a bunch of beeps that tell you that no video card is found.
posted by SpecialK at 5:02 PM on December 23, 2007

Damnit, aerotive, you beat me by mere SECONDS! fie on thee!
posted by SpecialK at 5:03 PM on December 23, 2007

If you're using UltraVNC with its video hook driver (which you should be, because VNC is pretty tiresome without it) then the graphics data supplied to you across the network is actually being sourced from your video card's graphics RAM. In that case, the video card is actually doing the work of turning Stuff into graphics.

If you want to run completely headless using VNC, you will need (a) a BIOS that lets you boot up your system without detecting a video card (sometimes all it takes to make this work is turning off a "stop on errors" BIOS option, and just letting it emit its mournful "no video card" beep every time you start it) and (b) a VNC server for Windows that includes a "fake video card" graphics driver for Windows to talk to.

I can't actually see this working terribly well (the UltraVNC video hook driver really does make the difference between sluggish standard VNC performance and a snappy responsive pleasure to use) so I'd recommend just fitting the oldest, least grunty video adapter you can find and using it with the UltraVNC hook driver.
posted by flabdablet at 5:16 PM on December 23, 2007

Hmm. Probably not then, but if this helps (i.e. if anyone knows where to look this thing up and understand the reference info) the motherboard is an Intel D850GB.
posted by Naberius at 5:53 PM on December 23, 2007

if this is the only way I plan to interact with that machine from now on, can I just pull the video card completely and run without one?

Wouldn't just testing that (remove card and restart) be faster than describing the problem here?
posted by rokusan at 6:12 PM on December 23, 2007

Well, it would give me a yes or no. But this way I get kind of a why. I'm woefully short of why in general...
posted by Naberius at 6:19 PM on December 23, 2007

I would leave the video card, just in case your connection goes wonky and you need to see it from the original system.
posted by slavlin at 7:19 PM on December 23, 2007

Currently released Windows builds will pretty much freak out without a video card of some sort.

If you're running FreeBSD/Linux/etc. Xvnc is available, it'll let you run a persistent Xserver available via VNC that isn't tied to any devices — it's all in memory.

I use it to run GUI P2P apps persistently on my headless fileserver, many of them using Wine.
posted by blasdelf at 7:56 PM on December 23, 2007

I would have said simply "no." It is interesting from a geek trivia perspective that there are "headless" servers out there, but your computer is almost certainly not one of them. You can pull your video card if there is a VGA port on the motherboard (ie, some other VGA port sticking out the back). Otherwise, Windows and / or your BIOS will not be happy.
posted by TeatimeGrommit at 8:51 PM on December 23, 2007

I have run normal boring systems (ie, not servers) headless (no monitor plugged in), but I don't think I've ever done it without a graphics card plugged in. Even the servers designed to run without a monitor still have a graphics card built in so that when something goes wrong and they stop responding to the network, you can get at them. This is not a common request, and I'd guess that it might be hard to really get working.
posted by cschneid at 9:45 PM on December 23, 2007

Well, actually, even the 'headless' servers on the market still usually have a serial terminal interface so that you can access a console of some sort to figure out whatsaborken when somethinsaborken and das blinkenlights ain't sayin' nuttin'.
posted by SpecialK at 10:34 PM on December 23, 2007

That board has an AGP 4X video slot - just find the cheapest, crappiest AGP card available on eBay, or pull one out of a dumpster-grade machine, and plug that in. Old cards don't have fans so they won't add to your noise, and the older the card, the less power it will suck. Any old AGP card will give you more video performance than you will ever need for VNC.

It's actually quite handy to have a video output available even on a usually headless box, since at some point you may well want to fool with BIOS settings. Much easier to do that without needing to get inside the box.
posted by flabdablet at 2:23 AM on December 24, 2007

I'm with flabdablet. While headless is possible, if what you're trying to do is reduce the heat and noise levels, just go down to a very low-end graphics card rather than no graphics card at all. Much less trouble / technical difficulty, handier in many situations, cheaper if you have to buy anything at all for the other solution, etc, etc.
posted by madmethods at 10:01 AM on December 24, 2007

What everyone else said, in total, is essentially correct. However, I want to point out that the Desktop is a function of the OS, not the hardware. You must have an OS to have a Desktop. There is nothing that says a Desktop is required--it's just the current metaphore in common use. Windows "forms" the Desktop by enumerating files in a specific special folder. The Desktop is just a ListView in Icons mode with the ability to set a background and some special handlers for the context menu, drag and drop, etc. If you shutdown explorer.exe it goes away, but the OS is still running.

And on Vista, if you run with the Aero theme, the Video card is doing a lot of the work, since it is a hardware accelerated theme and uses the DCE.
posted by jeffamaphone at 11:28 AM on December 24, 2007