CakeAlexS
My nvidia card is great, I know all the ATI users are just jealous.

 
 
Non-jealous Radeon user here...
 
Since my wife stole my newly built DAW a year ago (she had a good reason) I haven't had the chance to give it a workout, but haven't had any problems.  The PCIe mode switching is something I'll be looking into out of curiosity, but I haven't experienced anything related to it.
 

NVidia chipsets have previously (and may still) have performance issues with certain Widows settings.
With your Windows 7 setup - what are your performance options set to?

You can get to this screen by

• clicking on the Windows Start Button
• entering 'adjust performance' in the 'Search programs and files' edit box
• click on the link 'Adjust the appearance and performance of Windows' that will popup at the top to the list.

 
...Steven

TheSteven, thanks for the tips, but all the power/performance options in Windows and nVidia Control Panel were messed with which led to absolutely nothing!
************************************
UPDATE:  I have been contacted by the Level-2 tech support at nVidia. Below is the full questionaire with my responses in red and blue, sent 11/14/13. My hopes is that nVidia realizes there indeed is a driver/hardware issue and future driver updates consider and correct it. It's high hopes, I know...
 
Thanks for waiting. My colleague escalated your case to me for a 2nd look. From you description and troubleshooting, you may be looking at system/software incompatibility, some driver issue or hardware limitation. To clarify, do you get the latency/crackling audio only when using Sonar X2 app?  Overall, no.  Using LatencyMon.exe to check when playing iTunes and then moving some sort of graphics around (e.g. opening and scrolling a PDF document), I get even higher latencies on the dxgkrnl.sys and nvlddmkm.sys drivers then I see in Sonar X2...3.11ms and 2.43ms, respectively.  Simply by listening, these latencies will indeed result in crackles in the audio stream.  As for Sonar X2, I think one of the reasons why it is most prominent in said application is because some of the input audio streams (e.g. from recording equipment, synthesizers, etc.) have low-level signals and the music is not yet mastered, therefore gains and speaker/headphone monitor controls are turned up relatively high to maximize listening volume.  Therefore, the pops/crackles are more prominent "above" the incoming music/sound levels.

Are you able to play DVD/Youtube video without any audio issues?  Playing a DVD or an encoded movie seems to be OK when manipulating graphics; latencies are low.  When playing YouTube, it appears fine as well; latencies are low when manipulating graphics and there are no noticeable pops/crackles.  However, it should be noted that during these playbacks, the PCI mode is operating at PCI-E 16x2.0, verified by GPU-Z.  It seems that whenever the card is running in PCI-E 16x1.1 mode, the high latencies and crackles occur.  This is what happens in Sonar X2; the mode is PCI-E 16x1.1, and manipulating graphics results in high latencies and poor audio quality.  It should be noted that if I run a 3D game in a window-mode, and then open and use Sonar X2 while performing the same tests (i.e. moving audio bits and MIDI notes around, which is in effect, a graphical manipulation), the observed latencies are low and the crackles/pops do not occur as the GTX670 card is forced/remains in PCI-E 16x2.0 mode due to the 3D game running in parallel to the Sonar application.  Though fun, this isn't a preferred way to work! :-)

Since you already uninstalled/disabled the Nvidia HD audio driver, this driver should be causing any interference.  Unfortunately, uninstalling the nVidia HD audio driver and then disabling it has no effect on the audio quality/crackles.  I wish it would have improved it, but it did not.

Have you updated your motherboard SBIOS?  Yes, the motherboard BIOS is to the most current version of 2209.  Motherboard is Asus P5Q.  I thought about downgrading, but nothing in the various changelogs indicated any improvements in the PCI or audio-handling departments.

Also, have you updated the audio controller driver(Saffire audio)?  Yes, all Saffire audio drivers are the most current, as of the latest driver rollout that occured at the end of October.  It should be noted that these crackles/pops occurred even before loading the lastest drivers.  I did contact Focusrite, the manufacturer of the Saffire audio interface, and they told me that no reported issues/troubles with current drivers have come in to their office.  They do state that they've heard several issues that have come up over the years caused by high latencies, which have been narrowed down to nVidia cards and/or driver issues.  This is also been mentioned in online forums, notably Cakewalk's forum, which is the manufacturer of the Sonar X2 application.  The Focusrite tech also said that several DAW (digital audio workstation) manufacturers (e.g. Avid) do not recommend nVidia cards in computer builds that will be used for audio-intensive applications. Now, it may be that each situation is unique, but this is unfortunate none the less.

Lastly do you have any USB devices connected to the USB Ports?  Yes, I have several devices on the USB ports (mouse, keyboard, multi-card reader, keyboard interface, trigger pad interface, USB-Midi interface, and a synthesizer.  I unplugged all of them except, the keyboard and mouse, which I did move to other ports, restarted the computer and retested.  Playing music in iTunes and manipulating graphics resulted in the same thing--crackles/pops; no change.

Overall, based on my tests, the GTX670 card and/or its drivers are having an issue being in PCI-E 16x1.1 mode. It is in this mode where the problems occur.  Other than running a 3D game in the background, there is no way to force the card to say in PCI-E 16x2.0 mode.  I checked all my BIOS settings, and nothing is available.  Turning off power management options in Windows7 (PCI Express Link State Power Management-"OFF") and/or the nVidia control panel (Power Management Mode = Prefer Maximum Performance) has no positive effect.

Try this.
 
Please backup first.
Then check windows update again as recently there have been some performance and drivers fixes.

Do this, you might be surprised about what you find is missing:
http://forum.cakewalk.com/Driver-Boost-m2928792.aspx

Also go into Windows services, try stopping every service that contains the word nvidia.
 
Finally go to an administrative command prompt, and run sfc /scannow

Good luck....

GLORIOUS, BREAKTHROUGH UPDATE: I may have found a workaround/fix for the issue. After work, further testing and confirmation needs to be done. Once satisfied, I will post!

2:43AM
GLORIOUS, BREAKTHROUGH UPDATE

When X3 is working the way it should, that's exactly what it is.  
 

GLORIOUS, BREAKTHROUGH UPDATE
 

 
Moving on...

stevec
When X3 is working the way it should, that's exactly what it is.  

Exactly, "when it's working the way it should." But I'm sure they didn't cover this problem. After all, if the gum never loses flavor, then why chew another piece?

OK, here's the Green Day(?) update. Tests have confirmed snap, crackle and pop correction by about 80%. A shout out needs to go to some obscure post on a Native Instruments forum, coupled with a Linux forum!
 
We know the sound crackles are caused by the nVidia card operating in PCIe v1.1 mode. We must force the card to remain in PCIe v2.0 mode, but how? It's a thing called PowerMizer, and as far as I know, it isn't possible to tweak using accessible controls or power options. Instead we must go into... the... Registry!
 
WARNING: Registry hacks are needed. Proceed at your own risk and backup the registry before you do it.
 
The goal is to disable the PowerMizer function. One would think this is only something that is used on a laptop, but rest assured, I am on a desktop (er, rather floortop) PC!
 
The following is summarized and edited from the Native Instrument's forum:
 
1. Open up Regedit and go to:
\HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Video\$$$$$$\0000\
The $$$$ symbols will be random numbers, particular to your machine. Note there will be a few of them.  So open each one and pick the "0000" folder with the most keys in it.
 
2. Right-click within said "0000" folder and create new DWORD 32-Bit keys as listed below.
NOTE: It's best to name them accordingly as they're created.
PerfLevelSrc
PowerMizerEnable
PowermizerLevel
PowermizerLevelAC
 
3. After all have been created, double-click each one to open it.  Edit the Value data to the appropriate value listed below:
PerfLevelSrc to 3322
PowerMizerEnable to 0
PowermizerLevel to 1
PowermizerLevelAC to 1
 
4. Reboot and PowerMizer will be disabled! Verify your nVidia card remains in PCIe v2.0 mode by using the GPU-Z utility.  Test to see if crackles and pops are lessened.  Also check to see if you can squeeze out a better latency with your audio interface.
 
With this tweak, I reduced the snaps, crackles and pops by about 80% (best guess). They are still there, but very very minor compared to what it was. As for latency improvements, I am now down to 5.0ms with it being about 90% stable; about what it was before the tweaks...now just faster! More stability tests required.
 
The GTX670 runs cool and quiet; there is no fan speed increase. GPU clock is running not at full speed, but rather at 81% of rated. Memory clock, however, is at full-rated speed. Power consumption is reported as +10% over stock. Please note, that the card still runs "adaptively," meaning if a 3D application is loaded, then the card will ramp up to full potential. This is probably why the snaps, crackles and pops are only reduced about 80%.
 
Try it! See what happens!
 
More information (http://forums.opensuse.org/english/get-technical-help-here/hardware/410089-nvidia-powermizer-how-tweak.html):
PowerMizerEnable=___ = to switch it on or off (using hex codes)
PerfLevelSrc=#### = performance strategy where "22" is the code for fixed frequency and "33" for adaptive frequency, defined for battery and AC use.  Example, 3322.
PowerMizerDefault=___ = code to enable a performance level for battery use from 1 to 3, being from high (1) to low (3) performance.
PowerMizerDefault=___ = same as above but for AC power.
 
I suppose I could have made the PerfLevelSrc code "2222" instead of "3322" to force the card into fixed frequency no matter what it thinks it's powered by. I may try this. If it improves the numbers, I will revise.

Congrats on your efforts & findings!