[chrisriley]

Hi

My problem is regarding a CPU throttling issue on a Windows 2003 based server. When I run a 16 bit DOS based accounting package it initiates ntvdm.exe process which consumes approximately 50% of the CPU usage. However, the real problem arises when the 2-4 users connect to the server to use the aforementioned accounting package via terminal services. When each user loads a copy of the program another ntdvm.exe process is initiated thus resulting in CPU throttling at 100% and an unacceptably sluggish performance when users are operating the accounting program. I have googled this topic and read many other related posts and answers of which none seem to cure the problem. Has anybody got any ideas on how to resolve this problem?

Thanks in advance

Chris Riley

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Here's info I found:

Windows NT Virtual DOS Machine – Windows NT4/2000/XP/2003. Whenever you start a DOS or 16-bit Windows program (Windows 3.1 software, or a program designed for Win9x/NT4 but which has a mixture of 32-bit and 16-bit programming code) under Windows NT4/2000/XP/2003, that 16-bit program gets run by the Windows NT Virtual DOS Machine, NTVDM, which basically emulates a DOS/16-bit environment so that your program can run. There will be a different instance of NTVDM running for each DOS/16-bit program that you run. (Note that NTVDM in turns starts a different process called WOWEXEC).

Recommendation :
If NTVDM is in your Task List, you have a DOS or 16-bit program running. If it is twice in your Task List, you have two DOS or 16-bit programs running, etc... Leave alone; as soon as you close your running DOS/16-bit program(s), NTVDM will disappear from your Task List under Windows 2000/XP/2003 although it will remain in your Task List under Windows NT4 – under NT4 this is by design to ensure that the next 16-bit program you run loads faster.

Most of this you probably know. Other then updating to 32-bit apps or getting Windows Server 2003 R2,which may not be an option or cure the problem for you, I haven't much to offer.

Some references:

Slow File Server

Windows Server 2003-based Computer Becomes Slow...

Ron

[Major Payne]

Here's info I found:

Windows NT Virtual DOS Machine – Windows NT4/2000/XP/2003. Whenever you start a DOS or 16-bit Windows program (Windows 3.1 software, or a program designed for Win9x/NT4 but which has a mixture of 32-bit and 16-bit programming code) under Windows NT4/2000/XP/2003, that 16-bit program gets run by the Windows NT Virtual DOS Machine, NTVDM, which basically emulates a DOS/16-bit environment so that your program can run. There will be a different instance of NTVDM running for each DOS/16-bit program that you run. (Note that NTVDM in turns starts a different process called WOWEXEC).

Recommendation :
If NTVDM is in your Task List, you have a DOS or 16-bit program running. If it is twice in your Task List, you have two DOS or 16-bit programs running, etc... Leave alone; as soon as you close your running DOS/16-bit program(s), NTVDM will disappear from your Task List under Windows 2000/XP/2003 although it will remain in your Task List under Windows NT4 – under NT4 this is by design to ensure that the next 16-bit program you run loads faster.

Most of this you probably know. Other then updating to 32-bit apps or getting Windows Server 2003 R2,which may not be an option or cure the problem for you, I haven't much to offer.

Some references:

Slow File Server

Windows Server 2003-based Computer Becomes Slow...

Ron