My electricity bills are kinda silly each month at the moment too, i'm not sure how much crunching will affect them. so I'm crunching 24/7 on my laptop, which gets almost the same ppd as my desktop, then i set up 2x dual-cores (2.8ghz) at work to crunch. Hopefully that should keep my PPD up. I think i'm averaging close to 2.5k PPD now. I've been looking to undervolt my video-card to save on power while it idles, but i'm not sure how much energy going from 1.2v down to 1.0v would save on a 4850.