This thread has a lot of golden nuggets dropped in it. One reason why I gravitated to CW in the first place, was I was learning programming back in the day and resource management was key. SONAR as a host has to have efficient programming or it cannot work, and it is even more impressive to have it work on older/less capable machines (HUGE kudos to the bakers for this). The advancement of technology and RAM availability has made some programmers very sloppy as they "can" and is a lazy shortcut to making code "clean and efficient."
(Unfortunately,) a DAW creates an environment that allows for omission of the rehearsal phase. As mentioned above, using a bad take and tweaking the crap out of it or slapping on a ton of effects adds resource loading to any machine, and not all VSTs are created equal. It would be nice to have resource usage inside of SONAR to see "resource usage by plugin." The added time overhead/extra resources required to tweak a bad take definitely supports rehearsal/retakes as a better alternative. I personally try to minimize plug-ins just for this reason alone.
Tweaking things can cause more problems than not, as people see "one thing" with tweaks, and not the overall system effect of them. Brundlefly's post is a good one on simple, effective tweaks, and I agree that getting carried away with them can cause more harm than good.
This machine is almost 3 years old now, and back when I built it I had only one focus - streamlining data flow through the box. I went with 8GB of RAM initially just to stress test it, and ironically have never had "need" to upgrade it. Even editing video (which is cached to a magnetic HDD), I have worked on 12GB files without issues. The graphics load of SONAR is not big at all, so a "hard core" graphics card is not a "must," but as Mystic38 pointed out, the additional resources available (and less CPU usage) by a dedicated high-end card does benefit the system.
As far as "fan noise," I think this is another plug to have noise reduction inside SONAR as a feature request. I happen to own Audition, and for anything consistent, it is very slick to remove that noise. It is so good, in fact, that I have come to abuse this feature... I know the
Z3TA+2 video I made had a fan-driven ionic air purifier running the whole time about 4' from the mic - definitely NOT quiet, yet consistent, so noise reduction worked great. Audition's noise reduction is slick and powerful, and it would be nice for SONAR to have this right inside the host.
I will get in these stints to purposefully try to crash things "just for fun," and I have proven that the "dedicated DAW" is not necessary if the machine has the resources available. I run the onboard sound card all the time, and the ASIO aggregation of the Focusrite Saffire has added to my "brazenness" of running multiple programs simultaneously (through both sound interfaces now because of this feature). I actually do this quite often.
Interesting aside to the above... a couple weeks ago I decided to record 15 hours of tapes that I wanted to preserve. Simple stereo recordings, one track at a time. I needed to listen to them as I went, so I could take notes on sections to split out the tracks later on. That specific part made the evolution become as boring as watching paint dry, so I began tasking the system more and more to try to get a system crash... I saved the project between tracks, but started small... simple programs, then bigger and bigger until the last few tracks I was editing video, and
playing games (some pretty intense ones running full screen mode that required me to alt-tab back to SONAR to get time stamps of transitions). Yada, yada... bottom line... 15 hours later, after opening/closing programs galore, never rebooting the machine, and tracking/listening to these tapes, I failed to crash the machine
