I have this posted on the Windows 7 forum, too. 
 
I was getting some clicks in Sonar ran the DPC Latency checker. It shows a problem, which I can't find (if it really is a problem). However, the clicks in my recording program went away after I changed the buffer size for my USB connected recording device (a Roland Octa-Capture) and I'm not getting any other audio pops/clicks which could be a latency problem.

I've set "diagnostic startup" in the System Configuration panel, rebooted and ran the DPC latency checker program and the spikes are still there. I've disabled all the devices I could in the Device Manager and the spikes are still there. I disabled core parking on my i7 3770 in case that was causing anything and it didn't change anything. I've looked at other system tools and didn't see anything, that I could recognize, as a problem but I'll admit I'm not sure what I'm looking at on some of those panels.

The DPC Latency Checker will not run in Safe Mode so I can't test there.

I'm stumped on this one.
http://www.sevenforums.com/general-discussion/248244-dpc-latency-checker-shows-problem-but-i-cant-find.html
I haven't found out how to post pictures on here, if its even possible.  There is a snipping tool clip of the DPC latency checker screen posted on the Windows 7 forum. 
 
 

That looks like my current laptop's results... no matter how much stuff I turn off.

I'm sure you already know that adjusting the buffer size on your I/O is effective but it doesn't change the interrupts from other ops... it just lets the sound device tolerate the interrupts.

I wish there was some tool that we could use to identify what causes the interrupts... it's my impression that trial/error/observation is the only way to search out the troublemaker.

Good luck.


best regards,
mike

ouch... thats on a desktop?

Video drivers
network drivers
all power saving crap off

Yes, my new desktop.  As I mentioned, I've turned off everything I could find, no recording equipment is connected (or not powered on).  It does not have a wi-fi device.   I disconnected my iLok but that wasn't the cause either.

I don't know about the UEFI BIOS, if there is something there that is the culprit. 

One thing I notice is the disk activity light on the case is constantly flashing on and off, but it is not in sync with the spike frequency in the DPC display.  Its done that since day one, and I just assumed it has something to do with the SSD (??) since my other PC's with just conventional hard drives do not do that.

I actually lowered the buffer in my Octa-Capture.  I had never set the Octa-Capture buffer when I installed it on this new system.  I had noticed some latency which the buffer change fixed and the clicks in Sonar went away. 
 
UPDATE:  According to the DPC web site, this could be caused by a Kernal mode driver.  From their web site:
 
At a period of 3 seconds a kernel-mode driver in the system is stalling the CPU for about 3.5 milliseconds. So, every 3 seconds DPC latency is exceptional large and drop-outs in real-time data streams will typically occur

DPC latency is by definition a kernel mode driver hogging the CPU. Deferred procedure calls are where most ISR processing got moved to, so DPC latency is the modern day descendant of shared ISR problems. One wild possibility: there are some ethernet physical interface chips that need a CPU loop to operate whenever the cable gets plugged or unplugged. When unplugged, there could be a periodic (every couple of seconds) poll to look for it to get plugged in. Something to look for if your ethernet is not plugged in. Also, besides DPCLAT there is RATTV: http://msdn.microsoft.com...hardware/gg487354.aspx which could be useful to profile DPC execution times by driver stack.

I've disabled the Ethernet NIC's in the Device Manager (it has two) during my initial testing and disabling devices in the Device Manager and none made any difference.  I would 99% rule out any hardware devices as the problem.
 
I can see all the Kernal Mode drivers with a utility I downloaded. 
 
I'm wondering about the DPC Latency Checker program with an SSD as everything in the PC appears to be working properly, e.g. no PC audio cracks/pops (a common complaint on Win 7 systems), No clicks in Sonar, no other device problems, etc.   I don't have this problem with any other PC I have (a laptop and a desktop) and both have conventional hard drives, no SSD's.  The Laptop has Win 7 64 bit and Sonar installed (I have it set up so I can use it for on-site recording).  The other desktop is also a new build with an ASRock Z77 Professional motherboard and an i5 3550 CPU and Win 8 beta (it will get Win 7 64 bit installed possibly this weekend).  The other desktop will be configured as a backup for the main PC.  As it stands now, the DPC latency checker does not show any problems with the backup PC.
 

show the pick to my head tech since he happened to be in my office whist having this page up.....
quote "consistant spikes like that are 99% network"

FYI i have no pops clicks on win7..  it aint win7 doing it...

AHCI mode?
Intel management Control?
you didnt use ANY crap off the CD that came with mobo did you?

I want to throw something out there and I'm seeking corrections if applicable.

Isn't it true that some motherboards and their circuitry are just problematic while others, sometimes even the same model with a different bios revision may run smooth?

It seems hard to keep track of details like which motherboard has the greatest potential to run without interrupt but it's my impression that info like that is discovered as new items come to market.

Please correct or elaborate on any mistaken ideas I have just presented.


best regards,
mike

show the pick to my head tech since he happened to be in my office whist having this page up..... quote "consistant spikes like that are 99% network" FYI i have no pops clicks on win7..  it aint win7 doing it... AHCI mode? Intel management Control? you didnt use ANY crap off the CD that came with mobo did you?

Make sure no "tuning" applet is running in the background.
ie: EasyTune will cause DPC latency spikes if it's running in the background.


That's dismal for a desktop (or a laptop for that matter).
While rare, I have seen DPC latency spikes with some motherboards... where there was no resolution (other than a potential BIOS update).

Jim Roseberry

 you didnt use ANY crap off the CD that came with mobo did you?

Make sure no "tuning" applet is running in the background.
ie: EasyTune will cause DPC latency spikes if it's running in the background. 

exactly what i meant by crap on the cd... but will also say pretty much any of the drivers as well other than the nic just to get on the interweb