On Fri, 15 Jun 2007, M. Edward (Ed) Borasky wrote:
had very deep pipelines. If NWChem is anything like that, I'm not surprised the Intel compilers do a better job than GCC -- I don't think GCC knows much about all the specifics of tweaking such things as keeping data in caches, re-use, chip-level parallelism, etc. If NWChem is open source, I'm sure someone will come along and profile/tweak it.
Actually, gcc does not do a bad job at all for the x86, it's the performance of x86_64 code that sucks (so far). NWChem is not properly open source: the developers, at the NorthWest university, make it available (for free) on request, including sources, after filling in a form in which you agree not to redistribute it. Essentially they are glad if people use it, but want to retain control due to US export regulations (for some reasons some people think it is sort of strategic weapon? I don't know). It's good stuff anyway.
I wouldn't throw away that Intel compiler just yet. For that matter, I'd give serious consideration to switching to a Core 2 Duo and a copy of Intel's tuning tools ... they are quite good. Life's too short to wait for calculations. :)
Yes, sure. But also compiling, testing etc. kills heaps of time which I have better ways of using, e.g. publishing some good results of my calculations... :) bye Giacomo -- _________________________________________________________________ Giacomo Mulas <[EMAIL PROTECTED]> _________________________________________________________________ OSSERVATORIO ASTRONOMICO DI CAGLIARI Str. 54, Loc. Poggio dei Pini * 09012 Capoterra (CA) Tel. (OAC): +39 070 71180 248 Fax : +39 070 71180 222 Tel. (UNICA): +39 070 675 4916 _________________________________________________________________ "When the storms are raging around you, stay right where you are" (Freddy Mercury) _________________________________________________________________ -- This message has been scanned for viruses and dangerous content by MailScanner, and is believed to be clean. -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]