It's running at 1333, dual channel has nothing to do with the actual data rate it runs at, The DRAM is at a freq of 665, and this is DDR (DOUBLE data rate) so take true freq (665) x 2 = effective data rate (1330 or rounded to 1333). Dual channel is where the Memory takes the channels (each holding a stick of DRAM which is a 64 bit device) and 'sees' them as a single 128bit device. Can find more FAQs on DRAM here:
http://www.tomshardware.co.uk/ddr3-dram-faq,review-33220.html
and on the counter side, part 2 of my article, the 'fiction' here:
http://www.tomshardware.com/reviews/ddr-dram-myths,4155.html