Excessive Hardware Interrupts

I have a Dell Workstation (Optiplex 760) with a fresh install of Windows 7. Right from the get go, I noticed that the second core is running around 20-30%. Taskmgr is not that helpful so I installed Process Explorer. While reviewing the cpu information, Hardware Interrupts bounces between 20 and 35%. I downloaded RATTV3 and created a log file. After 5 minutes I checked the log file but to my disappointment the "Cumulative Histogram for:" is blank. It gives me all the information except the culprit!!! (bangs head on desk). After visiting Microsofts RATTV3 site, it states there is a known bug with vista and windows 7 in regards to displaying a blank value.

Is there any application available that can tell me the file name (drivers) that is causing the excessive hardware interrupts?

-- To give you a little background --

Windows 7 installed all drivers except HECI and SOL (AMT). I installed these which were available on Dell's website. Before these drivers were installed, I was still experiencing the second core cpu excessive usage.

There is nothing in task manager that points to high cpu usage (which is why I am using process manager).

I tried disabling common devices to see if the usage would drop down (all communication ports, NIC, Audio, HECI, SOL).


Anyone have a clue or experience this issue? Any help would be greatly appreciate.

If you're running 32-bit, Kernrate or Xperf. For 64-bit, Xperf. It's not trivial though. The aim is to work out which interrupt service routine (ISR), and hence which interrupt(s).

Try updating the BIOS and motherboard drivers, if possible. If the hardware is brand new, there's a possibility that something is broken. Interrupt storms are sometimes caused by a hardware device gone nuts.

Okay I will give that a shot. Yeah, I'm running 32bit. Its a brand new system and worked fine with Windows XP 32bit but I am now testing Windows 7 for production.

I haven't updated the BIOS but I will try that first thing tomorrow. As far as motherboard drivers go, I have already been that route.

Thanks again for the advice!

mikenewland77 said:

Okay I will give that a shot. Yeah, I'm running 32bit. Its a brand new system and worked fine with Windows XP 32bit but I am now testing Windows 7 for production.

I haven't updated the BIOS but I will try that first thing tomorrow. As far as motherboard drivers go, I have already been that route.

Thanks again for the advice!

No problem.

You might also want to check whether Dell perhaps recommends the use of a specific (non-default) HAL with that workstation. HAL mismatches can also sometimes yield that "one proc always semi-busy servicing interrupts" symptom.

Updating the BIOS fixed the issue!!! Thanks again for your help! I'm really digging Windows 7!!!