> > The 64 bit code is faster on Opterons by 10-30% as compared to > "identically compiled" 32 bit code. Not sure on EM64T. For older > Xeons, you can only run 32 bit code, so the point is somewhat moot. On our EMT64 testing we found that the 32bit versions run slightly faster than the 64bit versions. These are runtimes for various algos on a 3.0GHz EMT64: Algorithm 32Bit 64bit Wublastn 34.70 40.34 Wublastp 375.26 219.61 Wutblastn 785.54 713.88 genewise 95.16 113.99 exonerate 550.22 588.17 Cheers, Guy -- Dr. Guy Coates, Informatics System Group The Wellcome Trust Sanger Institute, Hinxton, Cambridge, CB10 1SA, UK Tel: +44 (0)1223 834244 ex 7199