For those interested in my particular issues, here's what I've tried so far:
-Revert to various older Nvidia drivers
-Perform general/extended system maintenance
-Verify Game cache integrity
-Auto config
-Tweak autoexec.cfg using various rates and other settings
-Set limit for FPS
-Change run time CPU priority and dedicated heapsize
-Set everything to "low" through the in game audio/video options
-Enable/Disable multicore
-Test individual single core usage
-Various runtime options including "-Threads" modes and "-mat_que_mode"
-Uninstalling/Reinstalling CS:S
-Test RAM for issues
-Test CPU/GPU for potential overheating issues
-Test network connection
-Test router for issues
All of the above changes/tests were done individually first to insure accurate results, with some later tested together for a potential increased effectiveness. The stress test gives me ~50FPS, actual in game FPS ranges between ~20 to ~40FPS; This is despite the various changes I've noticed above. The game should theoretically be 'playable' at 30 FPS, however the FPS I get in game is non-static and seems to rapidly stutter at random intervals. Further more I observed that enabling multicore whilst testing various "thread" and "mat_que_mode" setting yielded negligible FPS changes. I'm not running a lot of background processes, I perform routine maintenance on my machine both physical and software/OS wise. I have not noticed any similar issues with other games/programs recently on my machine.
I just want to be able to run CS:S again