I have run some comparisons of BLASTN searches between Apple Xserves (clustered and not clustered) vs large shared memory machines (sorry, no intel comparisons). See http://blastcompare.tamu.edu for details. Not surprisingly, the the Xserves were fastest at small word size. David L. Adelson, Ph.D. Associate Professor - Animal Genomics Dept. of Animal Science Dept. of Veterinary Anatomy and Public Health Faculty of Genetics Postal address: Animal Science Dept. Texas A&M University TAMU - 2471 College Station,TX 77843-2471 U.S.A. Office Tel. +1 979 845 2616 Office Fax. +1 979 845 6970 http://animalscience.tamu.edu/Gene/index.htm http://animalscience.tamu.edu/ansc/FACULTY/adelson.html