An average of 300 microseconds in DPC seems pretty high, whenever mine gets above 100 I look for issues. Nevertheless you're looking for peaks, not averages. Laptop power managent issues are notorious and you can't always get to them because the BIOS is often locked down. You can try using a program called Throttlestop which lets you disable things like C states and clamping in software. It's just a really light thing that runs in the background. Be careful though as some laptops handle their heat by limiting CPU speed/power.

Is there any way to post images here?

If you host them externally you can post a link.

What happens in DPC Latency checker if you run Sonar and get one of those spikes?

Hey, maybe I have just missed something here, but I don't see an external PC audio interface listed with your gear.
 
Are you using the audio chip that is built into the laptop by any chance?

He's got an Edirol UA-101.

check the control panel, sound device speaker thingy...open up your audio device preferences...and select the second tag.."playback / settings " select all boxes available wma , 44.1, 48, 96...all of them...and in the last tab...I do not have my pc on...make sure you test the setup..2 channel...ect...and do the record tab...ect.
 
Could be that?.
 
Just saying ...I have found after some updates...all this gets screwy.
 
Not sure about diagX...direct x set up any more...but one could find info in that once upon a time.
 
Hope it helps?
 
as for images...you have to wait (I believe , until you become more usery in time, on the forums:)...Then, you are allowed to do that.
I know I had issues doing it also first time round here....and it helped some see into my mayhem...which contradicted those who were trying to help me, but did not believe me...(good idea)....Had to use a online drive thing..upload the pictures, get the link...and try to post it...in the post...when you make a post...go into the options part....you might have to make some setup changes to your options?...took me a while, and i forgot how to now...i think if i remember now..a icon for links be clicked on?...options at the bottom of the page you open to post a new or add to, or is under, when in  quick post.
 
Cheers.
 
Sir Les

dwardzala
He's got an Edirol UA-101.

OK, see it now :-)
 
Then there is this from UA-101 Driver Ver.1.0.0 for Windows® 7 64-bit Edition readme:
 

Cautions and Limitations

• Sound interruption or other less-than-perfect outcomes may be experienced if your computer's performance and specifications are somewhat inadequate. The types of applications you use and the way in which you use them can also influence the experience you receive.
• On some computers, the driver does not load correctly if the UA-101 is already connected when Windows is started up. As a result, it will not be possible to use the UA-101 via USB. If this occurs, wait until after Windows has started to turn on the power of the UA-101 (or to connect it).
• If the UA-101 does not work correctly after resuming from Sleep mode, you should exit all applications that use the UA-101, and then turn the power of the UA-101 off and on again.
• If the USB cable is disconnected and reconnected while the UA-101 is in use, or if the power of the UA-101 is turned off, then on again, it may stop operating correctly. If this occurs, after resuming, you should exit all applications that use the UA-101, and turn the power of the UA-101 off, then on again.
• If your computer was experiencing a heavy processing load, such as when accessing a CD-ROM Drive or network while the UA-101 was being used, the UA-101 may no longer operate correctly. If this occurs, stop the playback or recording, then try starting playback or recording over again. If you are still unable to play back or record, quit all programs that are using the UA-101, then turn the UA-101 off and then on again.
• Audio clicks and pops may occur during playback or recording if you connect or disconnect other USB devices (such as USB memory) or turn another USB device on/off while using the UA-101.
• In some cases, you may not obtain the expected level of performance if you're using a USB-connected hard disk at the same time as the UA-101. Do not use a USB-connected hard disk as the storage destination for the audio that you're playing back or recording.

Wow...thanks abacab...sounds like usb is not the best thing....for audio with that device.
so yes device manager...usb tab..go into all usb hubs and such...preferences...power management tab, and do not let win turn off power to this device...or something liken, do to all....is a tweak said to do...in these forums!
 
 
if you did do...and had updates recently since doing any tweaks or settings made...check all of them again.
 
 

You can diag also in dos prompt /run as admin...enter: sfc /scannow      hit enter..let it run...it should complete the scan and give you a result/info..some say.....Not sure if it helps find corruption, but MS tier 2 techs do it all the time here remotely....always comes back OK...yet updates and such, not installing, and installed apps here, do not function properly, or at all, or some device liken internet intel or other not working or is seen as not in event viewer logs constantly being written to by...(corruption or conflicts with)...and event viewer is full of critical errors....Yet the scannow command finds nothing wrong....which I find amusing when done by them...Then they try other things in rush to try to fix...what the scan said has nothing wrong with it....seeing their hair fall out , is my frustration turned back on em ...lol.
 
Logging error takes cpu time away from...irq ..or interupts irqs in usage to do that event logging...so cpu hickups occur!
 
Circles eh?
 
Cheers.
 
Sir Les

and if so, cpu hickups = via irq interuption occurs...as spooling of intel is being collected and sent out by msn or bing...while you are online or off line..errors are then...made..noise on your audio...is one thing they cannot solve....nor can you...or anyone else...until irq is made exclusive for either or....and not doing that spooling and usage of services to spy...is done only when no usage of system is detected...for long time outs.
 
that said..if you disable internet and all other redundant devices before using any app...the spooling and caching continues to be done.
 
thus you will always have interupt of cpu/irq, and on a lap top...hard drive.....and disabled or not in use needed devices writing to logs...because service cannot complete or start to do...or are doing what should not be done...or at the time you are doing what needs be done...it is not letting be done until it does that task....and you cannot turn it off..by ULA agreements.