Do you have any kind of global illumination, plugin or otherwise? The env_map plugin thing increased my render time by like 3 on this one scene I was experimenting with fog. The fog didn't bother show up (no surprise), but without it corrected it and the render was rather fast. 52 minutes is a long time, complicated renders I tend to do overnight when I am in bed. Also, what kind of ram is it? Is there any animation, even though your not rendering it? Is that shader highly reflective or refractive? Shadows, render layers, fog, high bump depth? Everything can effect render time, some hardly at all, and some dramatically. Check your processes and make sure your processing power isn't being sucked up by a virus, virus blocker, spam blocker, ect. Always keep track of your processes. Windows updater is an annoyance when trying to optimize power.