Ditto, getting the same for all the 460/450's that I have. I can't verify the -bigadv, i'm running a P2686 and P2685 at crawl mode along with multiple gpu3 clients. THe P2685 apparently will make it by 27 minutes, mostly because it had a 6 hour downtime when I moved it to a new chassis. The P2686 is faring better, ~28K PPD using -smp 6 with 3 gpu3's running at the same time, though I expect it to go down soon.
Whatever they're doing I'm all for it, getting an extra ~5-8K is always nice.