Presumably, Intel has been holding back its Core i5 CPUs in an effort not to cannibalize the prodigious success of its Core 2 line, but the chips had to come out of the oven at some point. If Chinese sources are to be believed, that time could be early this September. As detailed above, the i5 mainstream offerings will start at 2.66GHz (Core i5-750), alongside two additions to the Core i7 family, the 860 (2.8GHz) and 870 (2.93GHz). The new parts are highlighted by 8MB of cache and Turbo Boost -- Intel's auto-overclocking system that speeds things up when your cooling allows it. Click through for another slide detailing Clarkdale plans for 2010, which seem to agree with earlier rumors on the subject. Mmm, fresh silicon.