grizwalter
First off, thanks a million, everyone, for all the help and answers/suggestions. This is truly eye-opening. What a fantastic forum. Hope I can pay it forward sometime!
 
Basically, it seems that the CPU, after all this, is still the most likely culprit. While the RAM functionality may be slowed down somewhat due to odd-matching, since RAM doesn't seem to have anything to do with this (using only 2.6 Gb tops in X3 no matter how much the audio drops out), there's no point in worrying too much about that. Wish I'd talked to you folks before I got more RAM, although, admittedly, 3 Gb was pretty pathetic anyway, and rather embarrassing to admit. lol
 
guigz2000, thanks for the additional info and link. I'll take a look at that. But either way, I'm 90% likely going to upgrade now. The info I have on my current Motherboard and CPU are as follows:
 
Manufacturer: ECS
Name: MCP61PM-HM
I have a second motherboard name which is labeled "HP/Compaq motherboard name," and that says "Nettle2-GL8E." I suppose that's just the name they give it for their computer package.
 
Current CPU: Athlon 64 X2 (B) 5000+ 2.6 GHz (65W)
 
Is that the correct info to figure out what new CPU will work? 

Ok, it seems that your mainboard will not accept bigger processor.It's an AM2 socket (AM2+ would have been better). An AMD phenom 1 X4 should work but there's no way to guarantee that without testing.
 
A better solution may be to get a new processor/mainboard. AMD one are very cheap and they work well (you won't get performances that great, but it definitely will be better than what you currently have). The cheapest Mainboard+Processor should be something like 110 euros and for the price, you should be able to get a 4 core 3.2GHz, with upgrade possibilities. Just check the memory type.
 
Nitenite

grizwalter
...people said that my A.R.T. Dual Pre unit is not an audio interface. That is incorrect. It is a preamplifier AND a Computer Audio Interface. I've had no problems with it whatsoever at any point previously, so let's take that out of the equation.

Apparently it's only a 16-bit device and it relies on the built-in Windows MMS drivers.  It looks to me like a weak link in the system.

You may want to go into each tracks prochannel and delete the ones that you are using. That seemed to open up some resources under the hood for a project that I was working on. I was having major dropouts on a project with 40 tracks or so until I did this.

grizwalter
To my mind, this is coming down to the unfortunate possible reality that what many people here have indicated is correct: RAM doesn't matter much. I find that incredibly hard to swallow and, frankly, disappointing. [...] A lot of people asked about the plug-ins involved, but like any 44 track mix, one can assume there are going to be a lot of them, and of course I understand they bear down on the system. However, that doesn't change the fact that upping the RAM SHOULD have helped a lot (considering more than doubling what I had), and instead it did absolutely nothing.

I haven't programmed any plugins, but I'm pretty sure most of what they do is calculations, and that means CPU cycles.  Most plugins probably use very little memory.  Synth samples, on the other hand as scook points out, are all memory and that's where ram will help the most.
 
 

bandso
You may want to go into each tracks prochannel and delete the ones that you are using. That seemed to open up some resources under the hood for a project that I was working on. I was having major dropouts on a project with 40 tracks or so until I did this.

That's a very good idea! Thanks for the suggestion. I'll definitely give it a try!

guigz2000,
 
Thanks again sir. Lucky me, huh?! Can't upgrade the CPU to a bigger one. I'll consider a new motherboard. You mention that it won't make a big performance difference, but will help, however, isn't one of the things I would be looking for in that upgrade a motherboard which can take a bigger CPU? If I did both, it would really get the job done I'd think, yes?

It's really a complex equation of things to come up with "what will fix the problem".  It seems that the two things possibly at issue here are the sound card/driver and/or the CPU.  USB devices "tend to" use more resources than some other things, so a great driver is really needed, especially if you are doing a lot with a bunch of channels at once, but if you are at the mix part of things and are just using the stereo out of that card, it would seem ok from the data throughput perspective.  That doesn't rule it out as the issue, however, especially since you are running a bunch of tracks with a bunch of plugs at 96k.  The 96k part CAN be helpful from a low latency achievable point of view, but not necessarily for overall performance at high load.  That's a lot of bits/bytes to push around.
 
The CPU is certainly suspect as well - and you know your options there.  Unfortunately, a motherboard/CPU replacement is a non-trivial upgrade.  Sure, it's easy enough to snap it all together, but to really do it right, you would have to rebuild the OS/apps/etc since the motherboard has some many functions - busses, cpu, memory, etc.  It would probably "work" if you just swapped it out once Windows figured it out, but it would be less than optimal and you may lose whatever gains you were hoping to get in the process.  It's better than it used to be under earlier versions of Windows, but I still wouldn't recommend doing it that way.
 
You said you have had other similar projects work, right?  Is it at all possible that there is just something wrong with the project or some plugin that's loading or something?  I've had projects that misbehaved with what seemed to be a lower requirement than other tunes that were absolutely more complex from all perspectives and determined that there was just something wrong.  It isn't easy to find or really to fix, but in the end, it was the only way I was able to complete the song: export the tracks, bring them into a new project and start adding everything back in one at a time.  Is there a "breaking point"?  can you "archive" (as in mute/solo/archive) some of the tracks a bit at a time and see if something drastically reduces the issues/cpu usage/whatever?
 
Hope this helps in some way.

Thanks Blades for the additional input.
 
I can tell you this is not a project related issue. I have had problems a few times; when I referred to working other projects of that many or more tracks, I was referring to the fact that I'd worked with them in MC6T and Sonar X3 prior to getting Sonar X3 Studio, and never had this problem. That's why it bothers me.
 
Someone above mentioned deleting all the not-in-use ProChannels and, frankly, outside of the obvious upgrading of the CPU/Motherboard, that's the smartest thing I've heard yet. I mean, considering I didn't have this problem in MC6T and Sonar X3, and considering the ProChannels is the only persistent difference between the two, that is a very logical thing to do, especially since that is a one-to-one direct relationship of additional "load" on the system--each track = one more case of a ProChannel. However, I'm pretty sure the ProChannels default to "off," and I can't see any way to delete an entire channel, just the modules within it (not including the QuadCurve EQ, which is locked I'm guessing). So any further tips or ideas on this are VERY welcomed!

Sorry if my post wasn't entirly clear. I believe that you are correct that you cannot delete the entire prochannel, just the modules inside (and the EQ is locked as far as I can tell). Removing the unused modules did seem to help my CPU meter usage drop even if the modules were off.

I believe that is correct with the unused modules, as SONAR is still processing them to a certain level "just in case" you switch them on during playback.