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

[Simon Clubley]

On 2022-12-19, Mark Daniel <mark.daniel at wasd.vsm.com.au> wrote:
>
> With this in mind I knocked-up a small program to repeatedly call a 
> function using $CMEXEC which calls a function using $CMKRNL and that is 
> that.  It measures how much effort is required compared to the simple 
> USER mode loop and reports it as b[ogo]VUPs.
>
> https://wasd.vsm.com.au/wasd_tmp/bogovups.c
>
> The real disappointment is my X86 VM.  The rest of the results seem in 
> line with expectations.
>

What numbers did you see ?

> PS.  Looking for ideas, suggestions, criticism(s), etc. here...
>

The tests still "feel" rather artificial.

My suggested alternative would be to write actual files away to disk
using RMS sequential files and also indexed files. Maybe read them
back as well.

Repeat the sequential files test using direct QIO access and see what
performance difference that gives when you bypass the transition to
executive mode.

(Yes, I know, RMS will add its own fixed overheads, but you will still
be able to see a percentage difference across the various machines you
are testing on and whether x86-64 VMS imposes a much higher performance
overhead.)

One obvious problem is that you will have to address issues round
caching in your tests.

Simon.

-- 
Simon Clubley, clubley at remove_me.eisner.decus.org-Earth.UFP
Walking destinations on a map are further away than they appear.