Zalman coolers focus more on noise-less operation than on cooling performance. I'd say that a Zalman HS with the fan at "low" you'd get about the same performance as the Intel HS but the fan would be virtually noise-less. At an average speed the Zalman would prolly cool better and still be quiter. If you wan't good cooling performance you should get a Thermalright HS like the SLK-900U, SLK-947U or SP94 and mount a good fan but not a Delta or a Tornado (unless you're deaf or want to be deaf).
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