Tom's had a great article on this very thing back in Nov 08.
It was interesting to run some of the benches in single, dual, and triple channel.
I ran the Performance Test app (from benchmark thread) and notice only one test that really stood out between single and triple channel, that test being Sorting Random Strings:
"The test uses qsort to continually sort 1000 strings of 256 characters. Once the test duration expires, the test reports the speed of the sorting in thousands of strings per second."
37.5% faster in triple channel.
Other than that, I can get about another 150 MHz stable by going to single channel when keeping every other setting the same.
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