In order to maximize ppd out of a high-performance cpu such as core i7. You need to take advantage of the bonus point system. There are bonus for returning WU quickly. The system applies to A3 core and -Bigadv folding. Below is a few guidelines:

1. Run the latest SMP client (v6.29 or above).
2. Configure that client with a passkey.
3. Complete 10 a2 and/or a3 work units...
a. within their preferred deadlines
b. using the same passkey and fah user name combination
c. on one or more of your systems.
4. Successfully return >=80% of assigned [bonus] WU's.
Once you got 10 WU finished. That specific passkey and user name will qualify for bonus point in A3 core SMP folding and -Bigadv. In order to monitor you bonus ppd, Fahspy and HFM.net both support bonus points calculations.

The bonus applies after you've done 10 a2 or a3 WUs provided you have used the same passkey and the same UserName on all applicable machines and provided you meet the 80% rule.

Once that requirement has been met, the bonus currently applies to a3 WUs and to bigadv projects (at least for the time being). You can tell by looking at the last column of psummary.
reference: http://foldingforum.org/viewtopic.php?f=58&t=13160