On 10/29/21 5:35 AM, jr wrote:
> hi,
> 
> William F Pokorny <ano### [at] anonymousorg> wrote:
>> ...
>> Not yet to profiling, but I've turned up a few things. First, I don't
>> see the +700% write side slow down you see, but rather about +280% so
>> this is more in line with your expectations for write vs read.
> 
> intend to install the new povr in the coming days.  will then run some tests,
> including another 100k.  thanks for posting the timings.  (1200% is a high price
> to pay, for convenience..  :-))
>

Ultimately it's user time which matters. If machines are paying and 
users still win measuring task time, it's the right trade off.

---
I understand more as of this morning. A large chunk of the p380 branch / 
povr slow down was due always-active soft asserts Christoph added to 
some of the last parser updates. These took me a while to understand and 
untangle/turn off for the 'regular' povr build.

So! Timing with my in hand povr.

stress_wr.pov
p380b1     ---> povr fld  6.87 -> 5.42 ---> -21.11%

p380b1 raw ---> fld +283.44%
povr   raw ---> fld +234.57% (-40%)


stress_rd.pov
p380b1     ---> povr fld  8.39 -> 6.38 ---> -23.98%

p380b1 raw ---> fld +1140.32%
povr   raw ---> fld +1103.77% (-36%)

So, I'm happy to see povr and likely P380 too, without the soft asserts, 
is quite a bit faster. I expect some of the speed up is due Christoph's 
newer parser updates and some due my changes, but I've not done the p380 
builds and timings to see how the savings break out - I'm not all that 
interested so that work probably won't happen.

A puzzle I've not been able to run down is the larger 'system' write 
times post v3.8 beta. It's very roughly around +12.5% of the raw and fld 
write slow down v3.8 beta to p380 (so it hits povr too though it's 
faster overall). Something is driving up that system time from raw and 
fld writes, but I've not been able to find it.

For now I'm walking away from it - Christoph cleaned up / changed quite 
a lot related to file and text streams over the last months ahead of the 
branch point for povr. I don't see an obvious cause - and my 
guesses(shots in the dark) as to cause have missed.

I hope to get to some actual code profiling today.

Bill P.

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