Safari wrote:
> On Sun, 03 Nov 2002 14:34:11 -0800, Roz <Rzl### [at] netscapenet> wrote:
>>Yes, that makes sense because they (Intel) should know all the ins and 
>>outs of
>>their own processor ;)  Looking back through old posts to this newsgroup 
>>there's
>>some indication that icc custom builds are just a tiny bit faster than gcc
> 
> 
> that tiny bit turns out to be 15-45% back here in Finland.
> ICC 6.0.1 on Linux[1] versus Official POV-Ray 3.50c:

Well now you've done it. After reading earlier posts I figured I could
skip the huge download of ICC (if it's still available for download). Now
you've tempted me into clobbering my poor modem connection ;)

Was this the official GCC compile of POV-Ray 3.50c for Linux you were
comparing speeds on or a more optimized one you compiled yourself?
The GCC compile I did is still a good bit faster than the official one.
Mark Gordon can't put too many special optimizations in the official
binary or he'd sacrifice compatibility.

My main thinking is that if I can make a compile using GCC that will
be very close in speed to whatever ICC can produce, then it's not
worth the hassle of downloading ICC and making a compile with it.

> was profiling (-prof_genx & -prof_use) used in the Windows version?
> it can speed up by 25%.
> option -pc80 seemed to speed up at least some scenes by 8%.
> also, remember to use -limf instead of -lm.
> -wp_ipo and -rcd seemed to break the compile at least with ICC 6.0.0,
> haven't tried with 6.0.1.

I've never tried the Intel compiler. Do you have a list of all the options
you recommend to use? I'll have to do some studying in between large
work related projects. *sigh*

>>builds. They're all so close to each other now that I'm not worried 
>>about it.
>>I just didn't want people to get the impression that the 10% slower thing
>>bstone mentioned was universal. There's many factors involved beyond the
>>compiler used including type of processor.
> 
> 
> like what scene files were used when generating profiling data
> with binary generated by icc -prof_genx ... ;)
>  

Exactly! Well I don't know the details of the option you're describing but
there was much left out of that 10% slower comment and I couldn't
just let it sit there without a response.

-Roz

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