HELP! Mac OSX vs. WinXP Multitasking Limits?!

Oh wow Jabjabs!!!! I didn't know that!!! Thanks!!! You say "Funnily enough" Should be "Sadly enough"... What's really sad is that all these WinXP users don't realize it.

I see I have almost nothing running now: 8 explorer windows, 4 IE, 2 IM, Ultraedit, 2 mytimers, 3 notepads, Realplayer, and a few things on my taskbar and I have 71 processes running. Maybe that explains part of the problem--if the system maxes out at 127 processes... hehehe... What a joke. I will look further into this. Maybe the problem isn't the "memory stack resources" but the limit on processes. >>EDIT: 5/16>> No I checked and found that it can run more than 127 processes--I was able to open 205 Notepad windows and it was running 224 processes. 54 IE or 54 Explorer or 205 Notepad. (The more complex the program, the more "Windows" it eats up. Photoshop probably eats up 10-15 windows). Something is limiting it but I don't know what. Maybe they should have called it Windows 54, not Windows XP. Maybe XP stands for a mathematical formula of how many windows you can open at a time . I am really wondering if Microsoft can explain this limitation or even admits it. I would think that it must be written somewhere at least for the developers?

Yeah, I've seen the capabilities of the Mac on Page 1 of this thread--500 pics open all at once! On Windows this would CRASH the machine (and windows will warn you "are you sure you want to open all these at once? This could be very slow" or something like that...

First of all let me say it's been a while, I started checking the forums again when the whole intel thing started. Anyways, the result of my personal multitasking challenge:

Windows XP- SUCKS... After 66 calculators open, the system couldn't open anything else (including task manager, of course, forcing me to shut down).

Kubuntu Linux- KICKS ***... 174 terminal windows open and no end in sight (at this point I figure linux just doesn't suffer from such a limitation, so i just didnt bother opening any more). System is still completely usable (posting from konqueror which is sitting pretty on top of the 174 terminal windows!).

Mac OS X- <realizes does not own a mac, sits in corner and cries for several hours>

Jabjabs said:

Funnily enough in XP you can only open 127 processes at once (tested using calculator) so I'm guessing that they have a 4bit addressing limit on multitasking.

As for my mac I have had literaly thousands of windows open and if you check my specs you will know that is very impressive. I'm not on my mac at the moment but when I get a chance I will post up a screenshot.

Click to expand...

thousands?? hahaha I would love to see that...it is impressive but also sort of funny

WIll the gyu with the Quad G5 Powermac see how many windows he can open before it stops, even if it is in the tens of thousands? This would be a great test.

When I get home on Saturday or Sunday I will give it a shot.....

Windows XP multitask

I found this thread becuase I was in a Windows XP multitaking discussion elsewhere, but it wasn't a contrast with Mac, just a really technical discusssion of how Windows works.

One thing that was pointed out was what really matters is *actual user experience* versus techicalities. For instance, does it really matter that you can't open more that 40 IE Windows? or more that 70 calculators?

I usually have at least 20 windows open at work running various programs and in never crashes.

As for OS X I know of people who have burned CDs, while downlloading, while rendering, while running quick time, etc, etc, and the system slowed, but sitll worked. I was impressed.

Then again, I know a Windows user who ran the HD defrag, and a virus scanner at the same time [constantly fighting for the HD], while burning a CD, and processing a major atronomy image, amd running itunes... and the itunes song never skipped, the system slowed, but was repsonsive. That impressed me...

I was most impressed by the Amiga user who moved his OS from one disk partitian to a second, and never stopped or rebooted the computer the whole time.

Well guys. I got 300 Safari windows and 300 Finder Windows. I only got a pic of the safari ones. The Computer was going slow after 300 of each. So i decided to just quit. If you guys want the 300 safari ones let me know

I have been using Windows since 1995 and the #1 most annoying thing is that I can't open many windows before Windows doesn't work anymore.

What I am specifically talking about is the inablity to open more than a couple large programs and a few windows, or just many windows. They should call it "few windows" instead of "windows". I wonder how many Windows one can open in Mac OSX.

Click to expand...

[MS hat on]

Ok, the issue here has nothing to do with any OS'es ability to multithread. The window limit you are hitting is a limitation in desktop heap memory. Every process that is opened in Windows gets a memory heap of 1MB that stays with the process until it is shut down. When that process is started and gets a Window on the desktop, it is assigned memory from the desktop heap. This memory is used for actually drawing the window on your screen with the GDI. It should be mentioned that this memory assignment is not memory that is used by the GPU, but is from Kernel Mode Memory space. If you see a depletion of desktop heap you can hang the system or even crash it. All Blue screen crashes originate in Kernel Mode memory.

BTW, if you are running with the /3GB switch you will have half as much Kernel mode memory and thus all of the various memory heaps in Kernel Mode will be halved. Some people try to run with /3GB (which is placed in boot.ini) because they believe it will allow a User Mode memory process to run with up to 3GB or physical ram. They thing they don't know is that it does this by taking away half of the available Kernel Mode memory. This is a common mistake in SQL server administration... but I digress.

You can adjust your desktop heap settings in this registry key:

\HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\SessionManager\SubSystems

SharedSection=1024,3072

That 3072 number is your desktop heap. If memory serves, the default is 512. If the SharedSection key is not there, the defaults are used. The first number, "1024" is your System Heap, as mentioned, "3072" is the Desktop heap, which is used by Interactive Processes (processes you interact with on your desktop) If there is a third number, it is used for Non Interactive Processes (services) MS recommends that Desktop Heap be set to 512, but that is too low for many processes. 3072 is usually too high. I've found that most issues can be solved by putting this setting to 1024. This setting will determine how many windows you can open. Of course this setting will also depend on how much memory you actually have in your system.

BTW, these settings are in KB.

So, in summary, the issue isn't one of multi threading/multi tasking which is a an activity of the Processor. It is an issue of memory management in a 32bit OS. Windows 64bit OSes will have similar limitations but of course those limits are much higher depending on how much memory you have.

I cannot say how a Mac handles desktop heaps, however I suspect that the 32bit memory architectures is similar in Intel based Macs because memory addressing with be the same. I've got a copy of "OS X Internals" on order. This book covers covers memory management and other high level topics on OS X.
http://www.amazon.com/Mac-OS-Internals-Systems-Approach/dp/0321278542/sr=8-1/qid=1163861362/ref=pd_bbs_1/102-3139803-5158524?ie=UTF8&s=books


BTW the Windows Internals book has been out for quite a while. It was written by Mark Russonovich (of SysInternals fame) and David Solomon. If you ever want to be serious in your career of supporting Windows OS'es, this book is a Must Read. Memory managment is covered in chapter 7.

I hope this helps

[/MS hat on]

While I think it is impressive that you can open 300 Safari Windows and 300 Finder Windows...I am not sure that it mattes it has that much to do with mulititaking. Multitaksing is really the ability of a computer to run many programs a the same time. I think both OS X and Win XP do nicley at this.

I checked again, and the Windows XP user I mentioned tested his computer and ran a virus scan, and defrag at the same time - with those two programs fighting over the HD I would think that would be it, but he was also able to burn a disk, while playing audio on itunes [without it skipping] and then open many megabytes of Astronomy pictures and unsharpen them, while do all this, he go on internet explorer and posted on a forum. That is multitaking.

Of course how pratical is tall this? Even at work I don't usually have more than 20 Windows open on XP and I am constantly opening and closes programs and I have no crashes. That is what you want from a computer OS.

roger31 said:

Of course how pratical is tall this? Even at work I don't usually have more than 20 Windows open on XP and I am constantly opening and closes programs and I have no crashes. That is what you want from a computer OS.

Click to expand...

Which of course is the real point. Any process that would require so many windows to be opened, should be automated and turned into a services. This can be done with an app called SrvAny. By turning a process into a service you can make it non-interactive and thus non dependent on desktop heap memory.

I just had to see how many mine would open and I decided to just open some images.

I opened 485 pictures from a vacation we took last year in safari. I didn't open anymore, but I will see what all I can open later. Posting the pic of the above. Will post more later.

With Win XP I was able to open over 40 in a tabbed brower, and this was with having about 10 other windows/pograms open and such. So I don't know about the 40 window limit.