Member Avatar for Bravus

Hi All

There have been previous threads here on related topics, and I've read them all carefully, but at this stage none of them has solved the issue I'm having.

It only happens if I play a 3D game (both Morrowind and UT 2004 Demo have exhibited it - I haven't tried others) and it's only been happening for the past day or so, since I installed a new Logitech keyboard and cordless mouse set.

All other computer operations will work fine, but on starting up games (ones that normally play fine on this machine) they will slow right down and get jerky. I checked the task manager and all the resources were shown as being in the System Idle Process (99%), but it also shows 70% (ranging up and down between 60-80%) CPU usage (this is after closing the games, and continues until I reboot). I used Process Explorer and it said that this usage was Hardware Interrupts.

I've installed the drivers for the keyboard and mouse, and updated the drivers for the video card, sound card and motherboard. I've also done very extensive (i.e. 3 different apps for each) virus and spyware scans and run Windows Update.

I suspect it's some kind of conflict with the new input devices, but I'm not sure what's going on. (And you shouldn't necessarily fixate on that - it could be something else that randomly cropped up about the same time!) Any help will be much appreciated.


Specs:

Athlon 64 3000+
Asus K8NE Deluxe (nForce 3)
Radeon 9800 Pro
1 GB RAM
Windows XP Pro SP2

  • 1 Contributor
  • 2 Replies
  • 124 Views
  • 20 Hours Discussion Span
  • Latest Post Latest Post by Bravus

Dani AI

Generated

This thread (and ' followup) is a textbook ISR/DPC problem: it looks like CPU use but the kernel is busy handling interrupts from a device or driver. When "Hardware Interrupts" shows up as the consumer of CPU, the root cause is almost always a bad or misconfigured kernel driver, firmware/BIOS setting, or a device repeatedly asserting interrupts. Below are practical diagnostics and fixes that work reliably.

Start with simple, non-destructive checks: run a latency tool to see spike patterns (for example DPC Latency Checker or LatencyMon), and capture a short live view with Process Explorer so you have timestamps to correlate. If spikes match disk or USB activity, open Device Manager and check IDE/ATA channel properties (Advanced Settings) to confirm transfer modes — a device that has fallen back to PIO will massively raise CPU/interrupt load. Then isolate by disabling one device class at a time (USB host controllers, network, audio, storage controllers) rather than removing software blindly. Create a restore point before changing drivers.

If isolation points to a chipset/IO controller, install the vendor-specific chipset/IDE/SATA driver and, if available, a BIOS update from the motherboard maker (avoid generic drivers from third parties). If updating doesn’t help, capture a kernel trace with the Windows Performance Toolkit (xperf/WPA) and share the trace with vendor support; that trace shows which driver issues the highest ISR/DPC times. Final cautions: avoid mixing trial drivers and always keep a known-good driver backup; document which change fixed the issue so future rollbacks are easy.

Useful references: Process Explorer, , and Microsoft docs on .

Member Avatar for Bravus

Still fighting this one. Thought it might be a USB conflict, so used an adaptor to plug the mouse into a PS/2 port instead. Thought that had fixed it for a minute, but nope.

Used a tool call 'Silent Runners' to check out what was running in the background and found 'powerreg scheduler', a piece of spyware that neither Adaware nor Spybot had found, so got rid of that... still no dice.

Someone in the other thread on a similar problem started by Cozzy suggested it could be the nVidia IDE drivers for my motherboard (which has the nForce 3 250 chipset), so that's the next attempt.

Member Avatar for Bravus

And as far as I can tell, that seems to have fixed it! Awesome job to Maggoth who suggested the solution in the other thread.

So, as far as I can tell, no real connection with the new hardware - maybe just synchronicity that it turned up at the same time... or maybe not.

Always remember, computers == v00d00!

Anyway, thanks - hope this little sequence is useful for someone else in the future.

Be a part of the DaniWeb community

We're a friendly, industry-focused community of developers, IT pros, digital marketers, and technology enthusiasts meeting, networking, learning, and sharing knowledge.