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

[Mark Daniel]

On 16/12/2022 10:27 pm, Mark Daniel wrote:
> Now, before everyone piles on, I understand the procedure provides an 
> indicative/comparative/finger-in-the-air measurement of the relative 
> performance of a VMS CPU relative to "the original VAX processor".
8< snip 8<

Thanks to all those who contributed to this thread.

The followup that caught my eye was from Simon Clubley who provided an 
entirely convincing explanation for the elevated X86 Kernel mode.

Also his pointer to BogoMips.  Most interesting.  I read the FAQ and 
accessed the github code.  Quite straighforward.  Might be a good 
replacement as a general performance metric.

https://github.com/vitalyvch/Bogo/blob/BogoMIPS_v1.3/bogomips.c

So taking the example general use implementation, modified it for 
building on VMS (and added some bits I find useful).

The only bit I am less sure of is the suppression of optimisation.  The 
above example uses a GCC-ism

|  for (i = loops; !!(i > 0); --i)
|    asm volatile ("" ::: "memory");

which I replaced with

|#pragma optimize save
|#pragma optimize level=0
|/* portable version */
|static void delay(long loops)
|{
|  long i;
|  for (i = loops; !!(i > 0); --i);
|}
|#pragma optimize restore

Anyway, the results were interesting (to say the least):

|$ mcr []bogomips
|HP rx2660  (1.40GHz/6.0MB) 4 CPUs 14335MB V8.4-2L1
|Calibrating delay loop.. ok - 692.73 BogoMips
|$ @vups
|HP rx2660 (1.40GHz/6.0MB) with 4 CPU and 14335MB running VMS V8.4-2L1
|INFO: Preventing endless loop (10$) on fast CPUs
|Approximate System VUPs Rating : 486.3 ( min: 483.8 max: 488.8 )

**
|$ mcr []bogomips
|Digital Personal WorkStation  1 CPU 1536MB V8.4-2L1
|Calibrating delay loop.. ok - 497.10 BogoMips
|$ @vups
|Digital Personal WorkStation with 1 CPU and 1536MB running VMS V8.4-2L1
|Approximate System VUPs Rating : 150.9 ( min: 149.4 max: 151.8 )

|$ mcr []bogomips
|AlphaServer DS20 500 MHz 2 CPUs 1536MB V8.4-2L2
|Calibrating delay loop.. ok - 488.06 BogoMips
|$ @vups
|AlphaServer DS20 500 MHz with 2 CPU and 1536MB running VMS V8.4-2L2
|Approximate System VUPs Rating : 250.7 ( min: 249.8 max: 251.2 )

|$ mcr []bogomips
|innotek GmbH VirtualBox 2 CPUs 7574MB V9.2
|Calibrating delay loop.. ok - 185.12 BogoMips
|$ @dvups
|innotek GmbH VirtualBox with 2 CPU and 7574MB running VMS V9.2
|Approximate System VUPs Rating : 275.9 ( min: 269.2 max: 286.6 )

For anyone interested my VMS bogomips.c can be found at

https://wasd.vsm.com.au/wasd_tmp/bogomips.c

** Interestingly, the PWS BogoMips matches the same model reported in 
the mini-Howto list of results:

> 21164A/500  PWS      494.88  Kenny Gryp <gryp at _dakin.be>
> 21164A/500  PWS      497.02  Robert Harley <robert.harley at _inria.fr>

https://www.clifton.nl/index.html?bogomips.html

-- 
Anyone, who using social-media, forms an opinion regarding anything 
other than the relative cuteness of this or that puppy-dog, needs 
seriously to examine their critical thinking.