Jump to content
Compatible Support Forums
Sign in to follow this  
papercut

SMP system, 50% cpu utilization by interupts

Recommended Posts

I am running the 120 eval version of win2k. I did not have problems with the earlier release canidates. I went from RC 2 to the final version and also added an epson stylus Photo 1200 printer at about the same time. Ever since then I have one processor worth of system load all the time (with a fairly constant 33% 67% split of the load). I looked at the number of interupts in the perfmonish app and they seemed high, but I do not know of any way to see what is generating the interupts. The rest of my hardware is a SB live value, voodoo3 3000, adaptech 2490 scsi 2 F/W controller a couple of IDE drives, a USR modem, and a realtec ne2000 PCI network card.

 

The system is responsive, everything seems to work (printer, mouse, internet connection, graphics.), but I would still like to find out what is causing the problem. I will probably start yanking cards out of the computer tonight if no one has any other ideas.

Share this post


Link to post

Using the Processes tab in the Task Manager, click on the CPU column (to sort by CPU usage), and see which process is actually using all your cycles...

 

Then tell us.

Share this post


Link to post

There is no process that is taking up the cycles (The idle process is at 90+%). The time is going to the OS (aka it the red and green graphs basically overlap.) This leads me to believe that it is a huge number of serviced interrupts that is taking all the time, but I don't know for sure. Could anyone let me know what a somewhat normal interupt/sec rate is?

Share this post


Link to post

The is no average or normal IRQ/sec rate for a machine. It depends on what's in it and what is running.

 

My SMP box, when quiecent (with BlackICE, OutLook, mIRC, Fax, AIM, Gozilla, MBM, etc running) is about 200/sec - if I open a QuickTime movie if goes up to 1500/sec. Your figure of 50% is somewhat meaningless smile

 

Many parallel printers now pass extensive status info back to the PC - it may be that this is causing the high level of interrupts you see. Try changing the BIOS settings of the port to ECP or EPP...

Share this post


Link to post

Problem solved!!!

 

After much reinstalling and nashing of teeth I finally changed the "computer" driver to MPS multiprocessor from ACPI multiproccessor. After that everything cleared up. BTW, when I said I had a lot of interupts I meant that it pegged the perfmon program at something like 100,000 interrupts/sec, far more that what I thought would be normal.

 

--Jason

Share this post


Link to post

Please sign in to comment

You will be able to leave a comment after signing in



Sign In Now
Sign in to follow this  

×