Announcement

**Lance Edmonds** · 5 Jun 2001, 07:58 PM

PowerBASIC allocates an initial stack frame of 1Mb. The remainder is app and data memory usage.

Remember, the disk file size bears no direct relationship to the amount of memory or resources an application may need. A better clue is given in the compiler results in the "memory image" statistic - this is the amount of memory occpied by the actual executable code when the app is loaded. The difference between the figure you qote and the memory image size will comprise the actual memory consumption by the running code.

In addition, this figure can change dynamically as Windows manages memory. This has been discussed on the BBS before (search for "workingsize" or "workingset" - off hand I don't recall the exact topic title)

In summary, this is quite normal and certainly nothing to worry about.

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Lance
PowerBASIC Support
mailto:[email protected][email protected]</A>

**Michael Meeks** · 5 Jun 2001, 09:33 PM

Lance,

What you say is true, but Win2000 goes beyond that. It's also
allocates some additional memory. You see this by opening the
Task Manager, place it to one side. Run your program.

While watching the Task Manager, minimize your program. My program
dropped to 170k. Restore the program, my 170k program grows to
about 2.5MB!

Although my program uses EZGUI and Cheetah Database, I can see
why it's allocated this amount. What's strange is that when it's
minimized in Win2k, it drops to 170kb (like a memory release).

Couldn't find anything on MS site pertain to this issue.

Thanks
MWM

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mwm

**Lance Edmonds** · 5 Jun 2001, 09:48 PM

I would not describe it as an "issue", but rather as a question on how Windows manages memory allocated to applications. I cannot see MS being too keen on disclosing all of their VMM techniques.

As I noted, Windows appears to dynamically free or allocate resources (memory, stack, etc) to applications. For example, when an app minimizes, no window redrawing will take place so I would assume that Windows frees some resources for the duration. While there is an API that can be used to minimize the amount of memory allocated to an app (SetProcessWorkingSet or something like that), but I don't see any "real" need to bother other than for "aesthetic" purposes.

Anyway, it is good to see you all take a keen interest in all aspects of the war on bloatware.

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Lance
PowerBASIC Support
mailto:[email protected][email protected]</A>

**Steve Hutchesson** · 5 Jun 2001, 10:04 PM

What Lance has mentioned translates out into 2 settings in a PE
file header, "Stack Reserve" and "Stack Commit", in laymens terms
the difference between what it will take if it can get it and what
a program needs.

Although most people who understand it have reservations about the
techniques that Microsoft use as memory management, the PE standard
currently runs across the range of 32 bit windows operating systems
and will probably continue to do so until Microsoft change the rules
so that they can sell more copies of a new version of windows.

Regards,

[email protected]

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**David Martin** · 6 Jun 2001, 05:50 AM

I mentioned something about this when PB/CC first came out. Never did get a reply.

Below is an excerpt from the PowerBasic website page http://www.powerbasic.com/products/pbcc/

"You know, a typical shopping cart program written in Visual Basic needs some 5 Megabytes of RAM. So, using VB, you may find you're limited to around 20 simultaneous connections. But use PB/CC instead, and memory needs plummet! To around 100K total! That means 1000 simultaneous connections on that very same Web Server!"

This statement does lead you to believe the memory usage is going to be around 100k not 1Mb.

**Lance Edmonds** · 6 Jun 2001, 05:56 AM

The key point to remember is that process memory consumption is totally "dynamic" and managed by Windows on your behalf...

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Lance
PowerBASIC Support
mailto:[email protected][email protected]</A>

**Eric Pearson** · 6 Jun 2001, 06:02 AM

It's important to keep in mind the difference between the amount of memory that is "currently allocated" for an application, and the amount that is "dedicated" to it.

As I understand it, the number that is being discussed -- the Mem Usage number that is displayed by the NT Task Manager -- is basically "the amount of memory that is available to an application without it having to ask for more".

When Windows starts an app it gives it lots of room to play. The app may or may not use all of the memory that is allocated to it. In fact it may request more if it needs to. And if another application needs memory, Windows can reduce the amount that is allocated to other applications.

If your app doesn't use the meg (or whatever) that is allocated to it, it's no big deal. Windows will give that memory to any app that needs it. If your app needs more, it can have it.

There are ways to artificially reduce the number that is displayed by Task Manager -- search this BBS for SetProcessWorkingSetSize -- but all that does is make you feel better. It actually hurts the performance of memory-intensive apps.

VB apps are "physically" much larger than comparable PB apps, and the huge VB runtime libary has to be loaded into memory whenever a VB program is run. That's memory that is dedicated to the application, so it is not available to other apps unless disk-memory swapping takes place.

So Yes, a PB program requires much, much less memory than a comparable VB app. The numbers that are shown by Task Manager are a gross over-simplification of "Mem Usage".

-- Eric

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Perfect Sync Development Tools
Perfect Sync Web Site
Contact Us: mailto:[email protected]fectsync.com [email protected]</A>

[This message has been edited by Eric Pearson (edited June 06, 2001).]

**Francis Beaulieu** · 6 Jun 2001, 06:23 AM

Thanks to every one!

I will be capable to sleep tonight!!

Lance your explanation was correct, but...
ratatatammmm... the one of Eric was very
very good! I took his word for it!

Then still have a nice day and take care
(of Vb huge memory spending)!!!

Bye!

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Francis Beaulieu
FrabLaser Softwares

Announcement

Funny but how a 8K can come into a 1116K???

Funny but how a 8K can come into a 1116K???

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