I just installed the latest beta on my Vista machine and notices that it uses
the SSE2 executable by default. I'm not sure what SSE2 is. Should I be using
it? The machine has a dual core processor.

-Mike

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"SharkD" <nomail@nomail> wrote:
> I just installed the latest beta on my Vista machine and notices that it uses
> the SSE2 executable by default. I'm not sure what SSE2 is. Should I be using
> it? The machine has a dual core processor.

In a nutshell, SSE2 is a processor feature that allows to do faster number
crunching (provided that programs are optimized to use it, which the
SSE2-binary of PoV ray is).

So yes, you *do* want it.


In a slightly bigger nutshell, SSE2 is a processor extension to speed up vector
math, by providing commands to apply a basic operation - like multiplication or
addition - to multiple numbers at the same time, and other handy things like a
combined multiply-add command which is a great help for matrix operations.

So it's a kind of parallel processing on a very small scale (which you get on
top of the large-scale parallel processing provided by the dual core).

The older SSE did basically the same, but only for vectors comprised of
single-precision floats or integers, which is not enough for PoV-ray; SSE2 does
this for the double-precision floating points used by PoV-ray.

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"clipka" <nomail@nomail> wrote:
> In a slightly bigger nutshell, SSE2 is a processor extension to speed up vector
> math, by providing commands to apply a basic operation - like multiplication or
> addition - to multiple numbers at the same time, and other handy things like a
> combined multiply-add command which is a great help for matrix operations.
>
> So it's a kind of parallel processing on a very small scale (which you get on
> top of the large-scale parallel processing provided by the dual core).
>
> The older SSE did basically the same, but only for vectors comprised of
> single-precision floats or integers, which is not enough for PoV-ray; SSE2 does
> this for the double-precision floating points used by PoV-ray.

I keep getting weird errors when using SSE2, along the lines of (not verbatim!):

"Unknown internal error!"
"Can't find source file."

I did manage to get the scene to render twice, though.

I'm using the non-SSE2 executable now, and it seems to be working without
problems. At least, it worked the first and only time, and hasn't stopped
rendering yet.

-Mike

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"SharkD" <nomail@nomail> wrote:
> I keep getting weird errors when using SSE2, along the lines of (not verbatim!):
>
> "Unknown internal error!"
> "Can't find source file."

Seen this, too. I seem to get things like this sporadically with MegaPOV 1.2.1
when I do too much file opening while it's parsing the scene file. Especially
when I open some other big file in the PoV GUI, and at the same time the scene
file parser needs to open an image or include file. Seems like it's hitting
some number-of-open-files limit.

Don't know about official PoV 3.6 or the 3.7 beta, because I haven't used them
much with huge scenes.

I don't think it's related to SSE2 in any way.

It *may* be possible though that the SSE2 version is compiled with other
differences in compiler settings that have an effect on this.

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"clipka" <nomail@nomail> wrote:
> Seen this, too. I seem to get things like this sporadically with MegaPOV 1.2.1
> when I do too much file opening while it's parsing the scene file. Especially
> when I open some other big file in the PoV GUI, and at the same time the scene
> file parser needs to open an image or include file. Seems like it's hitting
> some number-of-open-files limit.
>
> Don't know about official PoV 3.6 or the 3.7 beta, because I haven't used them
> much with huge scenes.
>
> I don't think it's related to SSE2 in any way.
>
> It *may* be possible though that the SSE2 version is compiled with other
> differences in compiler settings that have an effect on this.

If I don't use SSE2 do I still benefit from having two cores?

-Mike

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SharkD wrote:
> If I don't use SSE2 do I still benefit from having two cores?
> 
	With 3.6, you don't benefit from having two cores whether you use
the SSE2 version or not. With 3.7 beta, you do benefit from the dual
core whether you use the SSE2 or not.

		Jerome
- --
+------------------------- Jerome M. BERGER ---------------------+
|    mailto:jeb### [at] freefr      | ICQ:    238062172            |
|    http://jeberger.free.fr/     | Jabber: jeb### [at] jabberfr   |
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=?ISO-8859-1?Q?=22J=E9r=F4me_M=2E_Berger=22?= <jeb### [at] freefr> wrote:
>  With 3.6, you don't benefit from having two cores whether you use
> the SSE2 version or not. With 3.7 beta, you do benefit from the dual
> core whether you use the SSE2 or not.

Awesome! Thanks.

-Mike

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"clipka" <nomail@nomail> wrote in message 
news:web.493a9ed7644a75a06890bf690@news.povray.org...
> "SharkD" <nomail@nomail> wrote:
>> I keep getting weird errors when using SSE2, along the lines of (not 
>> verbatim!):
>>
>> "Unknown internal error!"
>> "Can't find source file."
>
> Seen this, too. I seem to get things like this sporadically with MegaPOV 
> 1.2.1
> when I do too much file opening while it's parsing the scene file. 
> Especially
> when I open some other big file in the PoV GUI, and at the same time the 
> scene
> file parser needs to open an image or include file. Seems like it's 
> hitting
> some number-of-open-files limit.

     Yes, I had this the other day too. I think I'm correct in saying that 
the max files viewable (tabbed) in the GUI is 32.

       ~Steve~

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"St." <dot### [at] dotcom> wrote:
>      Yes, I had this the other day too. I think I'm correct in saying that
> the max files viewable (tabbed) in the GUI is 32.
>
>        ~Steve~

I had the problem again, this time with the non-SSE2 version. It went away when
I closed the Explorer window I was using to view the directory I keep my source
files in. Maybe that's the problem.

-Mike

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"St." <dot### [at] dotcom> wrote:
> > Seen this, too. I seem to get things like this sporadically with MegaPOV
> > 1.2.1
> > when I do too much file opening while it's parsing the scene file.
> > Especially
> > when I open some other big file in the PoV GUI, and at the same time the
> > scene
> > file parser needs to open an image or include file. Seems like it's
> > hitting
> > some number-of-open-files limit.
>
>      Yes, I had this the other day too. I think I'm correct in saying that
> the max files viewable (tabbed) in the GUI is 32.

It actually seem to be an all-components-of-PoV limit, as it was in fact the
renderer which had trouble finding the files.

Not a good thing for a renderer striving for multi-core/cpu or even network
rendering.

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