Hunting the processing culprit

I have a project with about 20 audio tracks. Most of these have EQ on them. They route to buses with further effects such as echo and reverb. Half a dozen of them have automation envelopes on them, for volume or effects levels. Running X3 on Windows 7 64-bit. I've built much more complicated music on this same setup before many times.
 
After leaving this project for about six months, I have just re-opened it and now it crackles a lot. Bypassing effects globally causes all crackling to stop, so something in the effects or automation is causing the crackling. The CPU meters sit around 30-70% when FX is on, about 5-25% when bypassed.
 
To determine the CPU hog, I saved the project to a new name and started removing automation, then effects. One by one as I deleted an effect or automation envelope, the crackles gradually became less and less, and finally when all effects and automation were gone, the crackling was gone. 
 
But with all automation deleted and only 4-5 tracks with EQ still on them, I was still experiencing some crackling. Why? That's hardly anything. Last year I built a whole album with songs with tons or tracks and effects, never experienced this problem. I bought an SSD for Christmas and put everything on it but no difference.
 
My hardware is all the same, (except for the SSD, and I was having the same issue before I installed that). My synths, both soft and rack, are also the same. Everything's the same, except it's six months later.
 
Before someone says "corrupt project" let me also add that I made another song around the same time, and I'm experiencing new crackling with that one too. I haven't gone through all the investigative steps, but just in case someone claims it's unique to this project, it isn't.
 
Any ideas?

The thing of it is, whatever I'm using video/audio/accessory-wise is the same thing I was using six months ago. I don't use this computer for much else beyond Sonar projects. No NIC card, no gaming anything, relatively simple mouse. HDMI is used for one of my two monitors, but again, same setup as before.

any odd weather causing power brown outs or failures of electrical?....parts do ware out...
 
What about defrag?...any word on to do or not to do?....or was it done before moving the data to the new ssd?...

You say you are having "crackling," and the assumption is apparently that this is due to an overload of the processor. Assuming that the crackling is due to dropouts, it does not automatically follow that the problem is the result of processor overload. Anything that interrupts the flow of audio data can produce that symptom. For example, too small a buffer, or a look ahead buffer somewhere in the system can interrupt the flow even when you have plenty of computing power. What is the CPU meter showing in Sonar and in Windows when the crackling is there?
 
 
http://windows.microsoft.com/en-us/windows/view-cpu-utilization-performance-information#1TC=windows-7
 

M audio Delta not finding that completely as stated...but other models with more numbers at the end...like 10/10...etc/legacy cards and breakout boxes....could be something with the PCI buss?....check shared Irqs in the start /accessories/system tools /system info....and select irqs, and see what is sharing.....?
 

Just saying out loud...not to be a pest or Razz you to madness....
Remember things do not last forever, that Humans Make these days,...older stuff used well has a life span....Some of this new soldering technique used in modern gear, is in my opinion weakly done in ovens these days or rivers Just enough to stick the part on by robots, and when heated over time and time of use for long periods, soldered points can become loose or unsoldered at points of extreme heat build up...and may last 3-5 years...could go longer, but...that depends on a lot of things being put into place properly and maintained and cooled, some Asus capacitors for CPU on older boards I have had, can go bad and start leaking around cpu and onboard video card chips and such!...and certainly to help keep out the nasties of power supplied in smooth sine wave or good power bar, or back up to reduce spikes on electrical can increase life expectancy of the gear, upgraded from time to time....and the old stuff is nice, but has a life span....If nothing has changed....then it is time to rethink a new machine/audio device....Perhaps? as a legacy device is being used on a pci bus...it means you are a bit old in the usage of that system, and things do not last forever humans make these days........Perhaps is a direction one might ponder?

OK, so I've gone through all the posts (thank you!!) and here's what I've found:
 
No updates to video driver or OS, other than any automatic Windows updates.
 
It is indeed X3e.
 
Defrag happens automatically every week.
 
The audio interface is just listed as M-Audio Delta Audiophile. In the Sound dialog it lists S/PDIF, Line 1/2, and Multichannel. Line 1/2 is what I have selected as default. (I have no idea what any of those mean.)
 
As for the buffer sizes, I've changed them up and down everywhere between 64 and 2048, and no change has ever made any difference (to playback). That's in Sonar. The audio driver's interface is external to Sonar, and the ASIO/WDM buffer size is set at 256. Any other setting either higher or lower and the crackles get much, much worse.
 
As for the IRQ settings, M-Audio Delta Audiophile is at IRQ 16, which is shared with Intel ICH10 Family PCI Express Root Port 6 - 3A4A as well as Intel ICH10 Family USB Universal Host Controller - 3A37. At the bottom of this post is the System Summary from msinfo32.
 
I can ponder the outdated-ness of my gear, but before I bought a new system I would probably re-install Windows and start from scratch to see if things clear up. The idea of buying a new workstation makes me both giddy (new techie toy!) and depressed (re-installation and the inevitable Thing That Doesn't Work As Well As It Used To)
 
msinfo32 summary page:
 
OS Name Microsoft Windows 7 Home Premium
Version 6.1.7601 Service Pack 1 Build 7601
Other OS Description Not Available
OS Manufacturer Microsoft Corporation
System Name JIMOFFICE-PC
System Manufacturer ASUSTeK Computer INC.
System Model CM5571
System Type x64-based PC
Processor Pentium(R) Dual-Core CPU E5400 @ 2.70GHz, 2700 Mhz, 2 Core(s), 2 Logical Processor(s)
BIOS Version/Date American Megatrends Inc. 0221, 11/3/2009
SMBIOS Version 2.5
Windows Directory C:\Windows
System Directory C:\Windows\system32
Boot Device \Device\HarddiskVolume2
Locale United States
Hardware Abstraction Layer Version = "6.1.7601.17514"
User Name JimOffice-PC\Jim Office
Time Zone Pacific Standard Time
Installed Physical Memory (RAM) 6.00 GB
Total Physical Memory 5.75 GB
Available Physical Memory 1.59 GB
Total Virtual Memory 11.5 GB
Available Virtual Memory 5.17 GB
Page File Space 5.75 GB
Page File C:\pagefile.sys

could ram failure or unseating of sticks/dust cause this?  Also, I had lots of problems which began occurring from sketchy powerline which, even with a stabilizer/UPS, disappeared once I ran a new line... just reaching here...

Sounds like its your audio card buffer is too low.
 
You need to change the buffer on your audio card not sonar.  To do this go into your audio card software and change the buffer to 2048 then go into sonar and under the preferences menu click apply on the audio driver and it will pick up the sound cards buffer.  Then it should work fine

I see someone's already mentioned DPC Latency Checker, which will tell you if you have a DPC latency problem, but not much else.
 
Far more use is LatenceyMon, which will attempt to work out what the cause is. Download that from here:
 
http://www.resplendence.com/latencymon

jkoseattle
The thing of it is, whatever I'm using video/audio/accessory-wise is the same thing I was using six months ago.

Though this seems to be the most relevant thing, you kind of need to let it go because it only tells you not to try everything to fix it. You have to look at things it can't possibly be. I had a stutter on older projects last week. The now line would update every 1-2 seconds and not run smooth. Couldn't figure it out. My 2 monitors run off the i7 mobo on HDMI and DVI. I switched the HDMI to the main monitor and DVI to no. 2. That fixed it. And that couldn't have been a problem, but... I had a PCI card that had USB's on it and if I put the mouse on that card instead of the mobo all kinds of weird stuff went on. I threw out all PCI cards I had and only use PCIe for more USB or anything. If you have eliminated the possible or probable then only "it can't be that" is left. A wireless mouse of keyboard on a PCI card waiting around for it's turn can be a PIA. Unless  you have not updated Windows or any software your system is no the same as it was. Thinking "it worked on that latency setting before so it can't be that" is not true. So try what these guys are telling you. They are smart, have a lot of experience and want to see it fixed.                   

So no MB Manual of merit for this Motherboard...to seek irq share slots if any, or any nice pictures of it found Yet of the inners of that system, and others are having issues finding also.
 
So a windows System info...is ok...but the IRQ listing is what I want to see...and devices being used...please..
 
If you got internet device on, then turn it off, wi fi, turn it off...and then try again.
 
As I cannot truly see why one would put a below min system spec through the stress test, find problems, and ask what is wrong....When it is appearently the cpu and system is not capable of doing what you want to do with it perfectly as the builders ask for a standard be met first.....And I do not think you have.
 
And 4gb for windows 7 might be fine, but top that with EW which uses plugs to memory...or hardrive, and yet still used cpu loads....might just put that smoking cpu into fits of frantic convolutions...add some plugs ins...and you got problems!....Right?...so you got 6gb...not much difference really.

If you have a backup image more than 6 months old, you could always restore that as a sanity check. (Then load up the project and see if you get the crackles or not)

Just be sure to make a backup image from today so you can get yourself back to where you are now.

I have a Delta66 (not a million on miles different than your audiophile). If I get crackles like that, it's from high CPU usage, and increasing the Delta buffers will fix it. I'm just saying - that's where I'd look.