InsideHW.com has compared performances of Intel Core i7 for dual and triple channel memory mode
>> Intel Core i7: Dual-Channel vs. Triple-Channel Memory Mode
Intel Core i7 CPU introduced few novelties to desktop users and one among those was triple channel memory mode. This mode is supported by memory controller that is integrated into CPU itself. If you plan to upgrade to Core i7 platform one of advantages will be triple channel memory mode and with this test we offer you a straight answer to question: Is triple channel memory mode faster and better solution than dual channel mode?.
>> Intel Core i7: Dual-Channel vs. Triple-Channel Memory Mode