Okay first off:
How strong/weak your CPU is absolutely NOTHING to do with artifacts such as shimmering appearing in a game, how slow or fast your CPU is running will only determine how fast your game runs. Same goes for the PSU; The problems associated with the PSU are usually game crashes/system shut-downs. And how fast your PCI-E slot is running only determines how fast your card will run as well.
With artifacts that aren't part of the game such as shimmering, you can narrow it down to two culprits; Hardware and/or software
Artifacts in games can be caused by overclocking, so try running your card on vanilla (stock settings) settings and see how it goes
Also, go to Nvidia Control Panel and set "Texture filtering - Negative LOD Bias" to "Clamp"
But if shimmering is still apparent after all that, it's mostly likely your hardware and you'll have to RMA it in.
Hope this helps with your problems