Maximum Number of Open Windows under Windows? 34
Triones asks: "I have found that Windows 2000 has a limit on the number of
distinct windows that can be opened. W2K cannot open more
than around 70 distinct windows (duplicate IE's on the same
url don't count) even when it has 50Mb free phyiscal
memory and much more in system cache. The max I can get is
about 75 windows. Similar limits on machines with
256Mb or 512Mb ram. Some of my friends have reproduced this
phenomenon on their systems. (By the way, no such problem with Linux (Redhat,
XFree86, Gnome, Sawfish)). Is it related to the graphics
'resource' (GDI?) in Windows? Is there a parameter that can be
tuned to increase the limit? If this is a 'flaw', is it fixed in XP?"
Hmm... (Score:1)
Linux just has better resource managment, but I'm sure it has its limit aswell.
90 for me (Score:2, Insightful)
OK, I just opened 90 Notepads. Only 128MB RAM, on Windows 98SE. I guess Notepad isn't IE.
Also, on linux, I was under the impression that the virtual terminals *were* limited - when you compile a kernel the default is 256 ptys; I may just be utterly wrong here, but I thought that meant there was a 256 virtual terminal limit. I would presume it also applies to X - but does X open all of it's stuff in a single console terminal?
Re:90 for me (Score:4, Interesting)
linux virtual terminals/console (Score:2, Informative)
also, native X-Windows programs (excluding things like xterm and rxvt) do not usually open pseudo-terminals for themselves (you can see this using lsof or even ps). i think they utilize some feature of the X-Windows protocol to have the X server send messages to the console on their behalf (never done any X programming so not sure how that works). so while there may be a software-imposed limit to the number of xterms i could open, there isnt one for the number of games of xbill i could open.
mmm....hundreds of millions of dead Bill's...
see
--Siva
Re:90 for me (Score:1)
Resource limitations (Score:4, Interesting)
Office 2000 apps require in the range of 40MB of free memory. SCSIFiberPro 32 uses about 2MB. Winamp, Morpheus, etc. use 5-10 each.
That's not that much, however. What's really draining your memory is probably the services you're running.
LSASS uses only 1MB, so thats not a big deal, but SVCHOST uses 8-10, services.exe uses 10-ish, most of the others are in the 5-10 range, but there's about a dozen of them. With nothing running except for the services, I use 90MB of physical memory; it's about 105 when using IEXPLORE on top of that.
Windows doesn't have the best resource mangment available. However, Win 2K has considerably better than Windows 9x does - you'd crash long before you opened 70 some windows in one of those OSes.
(All numbers taken from the processes tab of Task Manager.)
JKoebel
The cat got my tongue! (Score:1, Informative)
Windows is too stupid to have such a limit (Score:1)
I wouldn't call it stupidity... (Score:1)
it's a feature (Score:2)
BTW what the hell do you need to open that many windows for? you don't even have grouping on your taskbar or the ability to create several workspaces/desktops and ALT-arrow between them like we do under Linux/Gnome. I can see your taskbar with each pixel representing a window must be real
Re:it's a feature (Score:2)
Re:it's a feature (Score:1)
Re:it's a feature (Score:1)
I currently have 4 desktops under litestep, which is plenty for me. The docs for the vwm don't appear to give a limit to the size, but I would think anything bigger than 3x3 or 4x4 is impractical.
Re:it's a feature (Score:2, Funny)
for porn, silly
--Siva
Re:it's a feature (Score:1)
http://hem.fyristorg.com/jspage/
Andrew
Re:it's a feature (Score:1)
Now the big question becomes "What to do with all these open prOn sites?
Re:it's a feature (Score:1)
I've seen a performance testing suite that simulated multiple simultaneous users to test remote cgis. It opened a window for every user and would probably run into trouble if it was being used to do stress testing.
Short answer: No hard limit in the OS. (Score:4, Informative)
The long answer is that the limit is dependant on the amount of memory in your system as well as a number of other factors.
The first factor is the amount of memory. This includes RAM and the page file. The second factor is the size of the each process running on the system. If you are openning a new process for each "window" (it was not clear from the description) then the amount of memory consumed is much higher than the amount of memory consumed by each new window in the same process. The third factor, and this is the big one, is the size of the file system cache. Windows dynamically decides how much memory should be devoted to file system cache at boot time and that limits the amount of memory available for everything else in the system (including other components of the operating system). The formula that Windows used to determine the optimal size of the file system cache takes into account many factors.
When available memory begins to run low then new processes may not be able to start and new windows may not be able to be created.
(correct email: miket@NOSPAM.telocity.com w/o the NOSPAM)
Re:Short answer: No hard limit in the OS. (Score:3, Informative)
Other than that, Win2K has the best memory managment that I've seen on a Windows OS.
JKoebel
Re:Short answer: No hard limit in the OS. (Score:1)
So my 'big' box has 256M of ram, so the swap is set to 768M. On my 'little' box which has only 64M, I set the swap to 384M.
GDI (Score:2)
Why? (Score:2)
Desktop heap size (Score:4, Informative)
To tweak the limit, take a look in the registry at HLKM/System/CurrentControlSet/Control/Session Manager/SubSystems - there is a key called "Windows" that contains (among other things) "SharedSection=1024,3072". Changing the SharedSection entry to "1024,3072,512" increases the size of the "hidden" desktop heap. If that doesn't work, try increasing the second of the comma delimited values (e.g. 3072 -> 4096), which is the size limit of any particular desktop heap.
I'm not sure if this is the limit the poster of this Ask Slashdot is hitting, but I do know that we have problems with this particular limit at work. We run an interpreted language/database/remote development environment, including customer applications as Windows Services. After stopping and starting the service multiple times, we get a USER32.DLL error for one or more of the executables running under that service - the only resolution is to reboot the machine, even after applying the aforementioned registry tweaks.
It is the GDI resources, not the memory (Score:1)
pr0n opened more than that.... (Score:1)
Back when I only had 64MB ram, win98SE would choke and die at about 35 windows of netscape...
Now with 512MB it can handle about 60 or so...Can't really count then because as someone said before, each task in the task bar is only about a pixel wide.
I wish my wife would get up the gumption to learn X/KDE so I can clean this virus off my computer and stop dual booting....
Is 70 windows really a limitation? (Score:3, Interesting)
An example of how this limitation would affect anybody would be interesting.
Re:Is 70 windows really a limitation? (Score:1)
I've hardly posted to Slashdot, before, but I felt I wanted to, now, because finally I've found somebody else mention this problem, as well.
As others have pointed out, it's a limit of the GDI-resources, and it's independent of how much memory you have.
I actually got 256 MB more in my PC (so I now have 384 MB), because I thought it was a memory problem, without it helping, at all.
I have 384 MB RAM, and I can't have 100 windows?! That's stupid!
This is actually one of the worst things I know about Windows, and yes, I'm using Windows 2000, the same limitation is there.
I had 4 MB RAM on my Acorn Archimedes computer, and I never ran into this problem, there. I had just as many windows open.
They got this right in 1989. Now, 12 years later, and with incredibly more powerful hardware, they still haven't got it right, in Windows. That says some.
It was asked for an example of how this limit would affect anybody, and I'll happily give that.
I tend to run into this limit, daily, and I think this limit, and the feature that you can't have the input focus at any other window than the top one (it automatically pops to top), to be some of the most annying things about Windows.
How I run into this limit?
It's simple. I tend to open IE windows in separate windows, so I don't get interrupted from the current one, and don't have to wait for them to load, to continue.
That also makes it easy to go to the other pages, instantly.
It's very convenient.
For example, I can read an article, and open any links in it, in new windows, so I don't get interrupted from the current article, and can go to them, later.
That means I don't get interrupted, and don't have to hunt for links, later.
Unfortunately, this conveniency is limited by the stupid limit in Windows.
Has anybody else had problems with this limit? Or are you all just using one window, and jumping in and out of the current article, when following links, and using the Back-button to get back?
Isn't that very disturbing on the reading?
Wouldn't it be better to have it in separate windows?
I've found using separate windows to be a better way of using the browser.
Regards,
Terje
P.S. Has anybody else found all this "My"-stuff to be incredibly infantile? "My Computer", "My Documents", My, My, My! Like a baby.
There's a very good article [salon.com] on Salon, about this.
Re:Is 70 windows really a limitation? (Score:1)
One poster mentioned that some may use this limit in Windows, to plug Linux, even if the limit is irrelevant for them.
I'm using Windows, and I can assure you the limit is very relevant.
In my opinion, there shouldn't be a hard-coded limit on the number of windows, in an operating system.
When the size isn't known in advance, use e.g. std::vector, not arrays, and you solve it.
Terje