NONMEM runtimes

From: "Rombout, Dr. Ferdinand" Subject: [NMusers] NONMEM runtimes Date: Mon, 29 Apr 2002 14:36:14 +0200 We investigated the runtimes of a standardized run on several computer systems and operating systems. We found that the runtime was linearly related to the declared SPECint2000 (not to others like Mhz or SpecFP) of the processor and almost independent of operating system and compiler if the most agressive optimization was used. We tested Silicon Graphics under Irix as operating system, and Intel/AMD with W2K, XP and Linux. Intel/AMD processors tested ranged from a PII at 400 Mhz to a PIV at 2 Ghz and Sgi was a 250Mhz R10K. We however had an important but unsolved problem under Linux above a Processor speed of around 1Ghz we saw no further improvement in runtime although we changed the processor type AMD vs Intel, Linux distribution, compiler brand, DDR versus Rambus, and NONMEM buffersize. So we saw a 42% decrease in runtime when switching a 1Ghz PIII to a 2 Ghz PIV which is close to the increase in SPECINT of 46%. Under Linux our runtime stayed about the same. Any suggestions as for an explanation? Regards, Ferdie Rombout