I figured I'd post this because there can be some confusion as to what we put in the readme (minimum requirements) versus what are the ideal requirements.
Click here for the recommended hardware for running Microstation V8i. Same recommendations apply to Projectwise Navigator V8i.
http://communities.bentley.com/products/microstation/w/microstation__wiki/microstation-v8i-system-requirements-and-hardware-recommendations-tn.aspx