i have 2-6in. hurricanes that are 630 cfm. not sure of rpm but right at 50 decibles cooling some 1000's inline . and have a 6 in. 449 cfm vortex pulling thru my carbon scrubber . the vortex is quieter than the hurricanes but are also moving alot less air . both have sweet 5yr. warranty and about the same price .
peace
Xcrispi