[Info-vax] VUPS.COM relevance for modern CPUs

[abrsvc]

On Tuesday, December 20, 2022 at 11:33:13 AM UTC-5, chris wrote:
> On 12/20/22 15:50, abrsvc wrote: 
> >> None of this makes much sense. spec.org have been devising cpu tests 
> >> for decades and have specialist tests for different workloads. That 
> >> includes all the info on compilers and code used. Probably the most 
> >> accurate data around and is supported by system and cpu vendors as 
> >> well. Too many variables involved, so some sort of level playing 
> >> field approach is the only way to get accuracy. 
> >> 
> >> Can be fun devising simple tests, but would never used that as a 
> >> basis for purchasing decisions... 
> >> 
> >> Chris 
> > 
> > The big problem with these standard benchmarks is that some compilers will look for these and insert some "special" optimizations specifically for those benchmarks. You are better served using a homegrown benchmark of some type that more closely reflects your application environment. 
> > 
> > Dan
> All the conditions are published, including compiler flags, 
> which compiler and more. Must be more accurate than a home 
> grown ad hoc test which ignores so many variables that could 
> influence the results. 
> 
> If you want to measure something, use the best and most 
> accurate tools available... 
> 
> Chris
I will disagree.  How many standard benchmarks bear any relevance to an actual application?  I suppose you can use them for relative machine performance information, but without knowing how your own application performs relative to those, they are useless.  SPEC benchmarks mean little to I/O bound applications.  Great, my new machine can perform calculations 10 times as fast.  But...  the application is bound by disk performance limits, so I see little to nothing for the speed improvement.  just one extreme example.