Windows 95 system resources decay over time

[SahraniKasim]

Hii...

I have a P100 with 64MB Ram PC which handle laser marking operation. It has got one A/D I/O card that controls the laser machine.The PC does 3 things :

1. Communicate with PLC (AB SLC500)
2. Control laser marking application (only runs on Win95)
3. Gets data from server (networked)

The problem is that the PC system resources decay to zero after sometime. I installed TaskInfo2003 from

http://www.iarsn.com

to see what's going on. I found out the laser marking application is using 100% of CPU capacity.

When the resources becomes zero, my laser marking will hang-up and burns the product. But this does not happen all the time or better word intermittently.

I tried to change the laser marking application priority from "Normal" to "Idel" or "Low" and suddenly the CPU usage dropped to 8%. However, th system resources still decay over time (after reboot is 88% and after 1 day 35%).

The questions are :

1. What causes system resources to decay over time ?
2. What does it really means by "High", "Normal" and "Low" priority.


Hope you guys can help.

Sahrani

 

[IRstuff]

It's a phenomenon called memory leakage. Programs running under Windows as well as Windows itself allocate virtual memory that does not get properly reclaimed. Over time, the operating system thinks that memory is getting less and less. You'll need to upgrade to a newer operating system or/and modify the application.

TTFN

 

[SahraniKasim]

Hi IRStuff,

Thanks for the reply. How do I flush out the not-properly-reclaimed virtual memory ?

Another thing, I have upgraded to Win98 last week and still seeing the decaying resources thing. I do not have an option to upgrade/modify the laser marking application since it's an old one. The OEM told me that newer version only works with new Laser system (that is about 100kUSD).

SahraniKasim

 

[IRstuff]

I don't think there is a way to do that. It requires knowledge that neither you, any other program or even your application apparently doesn't know.

Since you now have a means of monitoring the situation, when the memory drops below whatever you determine to be a critical threshold, e.g., prior to the operating system and application crashing, you'll need either close down and restart the application or reboot the operating system. It may be possible that closing the application will recover some of the lost memory, but that depends on the application.

TTFN

 

[SahraniKasim]

Just come back from my production line. We are seeing burnt product again. This time I checked the system resources are at 77%, and this really confused me. Previously it happened only when system resources is zero. When I wanted to reboot the system, it prompted me that 2 users are connected to the PC (1 unwanted user is accessing the PC).

Any comment ?

 

[IRstuff]

One thing that was a problem in Win95 that did not get corrected in Win98 is the graphics display interface (GDI) memory being too small. In many cases, particularly with graphics intensive applications, the GDI memory would get sucked down, sometimes independent of what other resources are doing.

Perhaps the other "user" was somehow using the graphics display resource more intensively.

TTFN

 

[Cato]

Hi SahraniKasim. Do you need the Network connection only for getting info from server?? or does the server need info from the PC. If it is only incomming traffic you may stop sharing resources over the net, so nobody can connect to your critical mission PC.

About releasing free memory allocated (but not in use) by programs, I had a similar problem in the past with win98. I got a program "MemTurbo" from

http://www.memturbo.com/

and it really worked fine. You can set some low memory trigger limits and it starts automatically recovering memory.

Cato

 

[SahraniKasim]

Hi Cato...
The PC needs info from server (server writes to the laser PC). How do I allow a specific PC/server to access a PC while blocking it from the rest of the network. RS232 is not an option due to the distance.

 

[Cato]

You have Windows 98 now, so if your server is a domain server (Win NT, Win200 or any Samba) you can choose the option of giving access only to some specific users.

In the Network properties window look for the tab "Access control". There you have two option "Resources access control" and "Users access control". I guess you have choosen the first one. Choose now the second option and put in the name of the domain where you want to choose the users list. Must be the same domain of your server.

Now while sharing folders you can what users to giva access (even read only or read & write access).

It would be a good idea to change you server admin password.

Hoping this would be useful.

Cato

 

[SahraniKasim]

Cato,

Thanks for the advice. Will try that soon...

Sahrani

 

[jnims]

Have you looked to see if you can eliminate any programs that are loading when the system starts up? I was having problems on my home computer with low resources and did some searching on which programs can safely be eliminated from automatically starting. Here are a couple of the links I found.

http://www.hp.com/cposupport/personal_computing/support_doc/bph06569.html

http://www.pacs-portal.co.uk/startup_content.htm

Please note that I am a computer novice and do not have any experience with process control.

Hope this helps.

 

[bwatson0]

I believe there is a utility in Win98 called MSConfig (you can run it by going to Start->Run and typing msconfig. There you can configure which applications and/or processes load when Windows loads.

As far as the memory leaks are concerned, that's just Windows for ya. There are tools available on the net for reclaiming your lost memory. One such tool I remember is called FreeMem. Do a search for it on google. I think its free. Basically, it simulates a request to run a "memory hog" program and Windows allocates the memory. It then properly "closes" this "program" and poof, you have more memory.

 

[hacksaw]

you might try adjusting vcache in the "sys.ini" file(run sysedit).windows tends to cache HD files but does not free up the space. this can lead to progressive increase in memory resources (other programs can also play a role).it comes in very handy if you only have 4 meg or 8 megs of ram, but it is very useful when you have larger amounts of memory.


for example:

[vcache]
minFileCache=16384
maxFileCache=32768

this sets the min file caching to 16 megs and the max to 32 megs.

you can also run a windows NT code called "clearmem.exe" every so often. it frees up (or purges) all unused memory. it works fine in win 96b. it prob. works in win95 and win95A.

although win 98 is quite a bit slower and uses more memory, and uses a lot of processor capability; if you install win 98SE upgrade you will find that the memory manager is much better at limiting the progressive loss of available memory.

 

[panda2525]

One solution could be to place a larger hard drive in this computer (like 10 Gb) and make the virtual memory file (swap file) larger in size. That way as the program that is hogging the recources starts to use up more memory, Windows should automatically free up more phsyical memory by swapping the data stored in RAM on to the Hard drive. This doesn't stop the problem, it justs slows the problem down so that you maybe able to go a few days longer before you would need to address the problem with a reboot of the computer.

-----------------------

http://www.panda.net.au

 

[SahraniKasim]

Thanks everyone.

With task manage downloaded from

http://www.iarsn.com,

I could monitor system indices. I realized that everything except CPU usage is OK.

After running the laser marking application for 4 hours, the CPU usage becomes 100% and I can only bring it back to minimal by rebooting the PC. Why this happena dn hwo do I tackle this problem?? Thanks in advance.

 

[IRstuff]

Depends on more details about how the application is running under the operating system. It might be simply that the program is a memory hog and not releasing unused memory for later re-use.

There are supposedly programs that can recover lost memory, but you still might need to unload the program at the minimum.

In some cases, it might be Windows itself that's honked up, in which case, you'll definitely have to reboot.

TTFN

 

[hacksaw]

what do you mean by system resources? you need to be specific.

have you tracked usage of available memory with time?

 

[lrecord]

I see a lot of Windows bashing going on here, and for obvious reasons it's justified, but a memory leak can be the application's fault as well as the OS. If you kill the suspect application and resources come back to close to normal without having to reboot the OS, then it's an application leak. If the resources only come back slightly (equivalemt to the application itself) then it's definitely an OS leak.

 

[hacksaw]

windows bashing, not here, we're just dealing with a few of the un-documented features...

 

[bwatson0]

Obviously "memory leak" is a term that can apply to both the OS and a specific application. I've seen both cases. However, it has been my experience that it is very common in both MS applications and OS's. As hacksaw mentioned, one of their many "un-documented features".