Hi all,
 
I know much has been written here on this topic but I'm out of ideas and have hit a wall with this problem. My setup has worked fairly smoothly but the pops and clicks issue has never been 100% resolved. Now it's costing me takes that I'd prefer to keep but have to discard.
 
My setup is old. Upgrading isn't an option so I have to work with what I have. Here's the rundown:
 
Sonar 6 PE (with all patches)
Dell Inspiron 530
Windows Vista Home Premium (SP2)
Intel Core 2 Duo E7400 CPU, 2.8 GHz
8 GB RAM
M-Audio NRV-10 Firewire Interface
Firewire adapter with TI chipset
M-Audio Audiophile 192 sound card (I used to use this for recording, now it's just there acting as a regular old audio card)
What else? Um...
Invidia GeForce GT 240 video card, which I initially bought because the original integrated card was causing pops. Now, the noise seems to be related to graphics again (they sometimes correspond with graphics changes on the screen). The problem is I'm not sure how to diagnose.
 
I ran LatencyMon and the results were not good. I received this message: "Your system appears to be having trouble handling real-time audio and other tasks. You are likely to experience buffer underruns appearing as drop outs, clicks or pop. One or more DPC routines that belong to a driver running your system appear to be executing for too long. One problem may be related to power management, disable CPU throttling settings [note: they are disabled] in Control Panel and BIOS setup [note: I can't access this with the BIOS interface on this machine for some reason. Online it looks like other people have more menu options. Not sure why this is.] Check for BIOS updates. [Did that. No joy.]"
 
The pops and clicks seem to only happen when recording out of box. Soft synths are fine, but if I run an instrument or mic through the NRV-10, the problem emerges. A real bummer.
 
I've noticed an instance of svchost in Task Manager that's eating up over a million K, so I've been in the habit of just killing that before tracking. No ill effects and some stability/better performance as a result. But there are CPU spikes that occasionally freeze Sonar for a few seconds.
 
This is where the sidewalk ends for my problem solving. I don't know what else to pursue. Anyone have any ideas?
 
 
 
 

Have you recently enabled or added WiFi or Blutooth hareware/drivers to the system? They are notorious causing DPC latency spikes. LatencyMon should give you some indication of which driver is causing the problem.
 
A change in real-time back-up or anti-virus configuration can also play hell with audio streaming. I had a problem a while ago where Microsoft Security Essentials 'real-time protection' had become spontaneously enabled, causing it to scan all audio accessed by the project when it was loaded. But that was more about HD usage than CPU. I could see the MSE process hogging the disk in Resource Monitor.

Since Vista is no longer supported, either by Cakewalk nor Microsoft, I'd suggest disabling Windows Updates. Quite possibly your system is trying to find updates that aren't there. I've seen a Vista laptop burn a 3 hour battery down in 45 minutes due to this.
 
Dan
 
 

Off the top of my head, here are some things you might look into if you haven't already investigated them. PCI latency (video cards can hog resources). Are your video card drivers up to date? Now that I think of it, have you tried different drivers for the NRV-10 (in my experience with a different M-Audio interface, the newest drivers didn't always work the best)? Have you tried disabling the Audiophile 192 while you're recording with the NRV-10? Are there any other non-essential services you can disable while using SONAR.
 

Look at the Drivers tab in latency monitor. What dlls have the highest execution latency, then what do those drivers do.

If you are on a laptop, consider disabling the battery charger and power supply as well as blue tooth and Wi-Fi.

I don't recommend killing svc host.

One time I switched my mouse and the mouse driver caused a click until I downloaded the driver from the mouse maker.

This is a 2008 Desktop with pretty minimal specs. But that said the OP is totally living in the era with both Audio interfaces an Software versions. 
If you folks will remember those days posts like this were common. 
There is so much that could be going wrong it's not funny. 
From the OS, the CPU, the old audio cards... 
First the OS was a huge hog and one of the worst for DAW's.  It needs severe doctoring to get it from having 90 processes running. With that CPU this is your first mission. Background processing nukes until Latency Monitor gives you a green light. 
 
You really are expecting  bit to much when you don't keep at least close to up to date with a DAW system. 
 
 

Idk, I ran a daw prior to 2008. It worked ok.

Vista was never good for audio. We had substantial problems with Vista.
You have more as the double performance with Windows 7.
The first I would do is installing Windows 7 (works perfect with Sonar 6). You can get a legal Windows 7 Home as a download version for about 20$. In my opinion the problem is Windows Vista.
 

Go to Device Manager. Disable your network device(s). Open Sonar and try again. Highly likely you'll hear noticeably less clicks or pops.

When not using Sonar, open Device Manager and re-enable your network device.

It's about three clicks to do the disable / re-enable, so not an unreasonable trade to eliminate the clicks and pops without buying a new PC.