Looks like we have a serious competitor to the Gigabyte GA-965P-DQ6. The ASUS P5B Deluxe at 490 x 6 aircooled using X6800 CPU. The CPU is run at 6 x 490MHz with ram running at 1:1 at DDR2-980 CAS 5, 6-6-15 2T. DDR2 voltage at 2.15v and the rest is default voltage. SuperPI completes running without an issue.

OCWorkbench