Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!ucbvax!agate!shelby!polya!Teknowledge.COM!vaxc!uw-beaver!rice!sun-spots-request From: rwood@vajra.dec.com (Richard Wood) Newsgroups: comp.sys.sun Subject: Re: RISC MIPS -- Sun vs. VA Keywords: Miscellaneous Message-ID: <1778@brazos.Rice.edu> Date: 28 Sep 89 18:17:54 GMT Sender: USENET News SystemOrganization: Sun-Spots Lines: 34 Approved: Sun-Spots@rice.edu X-Sun-Spots-Digest: Volume 8, Issue 143, message 2 of 10 One significant point of contention about the meaning of "MIPS" is the fact that no commonly used test or benchmark measures only the hardware of the system. Each will measure a different blend of raw hardware speed (which combines many related subsystems) as well as OS performance and compiler efficiency. Most of the earlier MIPS ratings cited by vendors in the UNIX market benchmarked their machines against a VAX 11/780 running 4.1BSD or 4.2BSD. Since those are both quite a few years old, they aren't really valid measurements now. Thus the performance of an 11/780 changes over time - today's software will deliver more power than yesterday's. Since any VAX running a contemporary copy of VMS and it's compilers will out-perform the equivalent hardware running 4.2, there is a distinct bias. Digital realized this bias was being used as a marketing weapon, and started using the term "VUPS", for VAX Units of Processing, defined as the performance of a VAX 11/780 running the most recent VMS software. The most recent Ultrix software will perform roughly the same (a little better in C-based programs, a little worse in Fortran-based - due mostly to the design intentions of the OS, as opposed to compiler quality). Digital Review uses MVUPS as the basis for their quite well thought out suite of tests. Of course, now most vendors that compete directly with Digital use the term "VAX MIPS" (or even VUPS) when claiming performance numbers. Whether these figures are adjusted for the differences in OS/Compilers can only be known by that companies marketing people. The only sure way of testing the performance of any machine is to run the application mix you intend to use on the machines you are considering. Failing that, pay more attention to independent tests such as those in industry magazines. Vendor claims should be thought of as the propaganda they usually are.