Maestro6... update your sig to reflect your system specs.
170 instrument orchestral tracks with your cpu and memory is kinda extreme; it will take a
long time to load, no matter the DAW. CPU hit is also huge...and I can't imagine not getting memory warnings, resulting in dropouts and system instability. I do when I get too crazy with templates and I got 6 lovely cores...unfortunately, core balancing is challenging and not related to Sonar. It's why lots of ViC folks use multiple synced machines...
It doesn't matter that there's nothing on the tracks...they are loaded and active... especially when you press play or record. I can slam my much more robust cpu with just two instances of Omnisphere2 using Airwaves multies...
Doesn't matter the DAW... then again, you say it was ok befor... really?
FWIW, I notice no discernible difference in load times, even with several ips tracks and the new "DanaMania" png track icons on my vocal tracks. I did load up a bunch of kontakt templates with Project Sam, Spitfire, and other configurations and as befor, got the mem warnings and my system became unstable... 100+ heavy duty memory hogs do it every time...
Often I delete lots of a template as I go along...as I'm not using everything.
I wish we had a "delete all tracks not being used" button! Would make it easier loading templates, muckin' round, cleaning them up and loading another.