Sorry if this question has been posted and answered somewhere, but I
have searched the postings and faqs and can find nothing on it.

I have a newish eMachine (low priced PC) with an AMD 333Mhz K2 that
renders all my old povray scenes slower than my laptop with a 120Mhz
Pentium (like 1/3 the speed rather than 3 times faster, as I would think
it should). This very slow rendering performance occurs under both the
Win98 and Mandrake Linux 6.0 OS installations on the eMachine so it does
not appear to be a OS or software installation problem to me. (Perhaps
the K2's L2 cache? but the laptop is older and only has smallish
processor cache anyway.)

Any information would be greatly appreciated.

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Scott Sexton & David Lewis wrote:
> 
> Sorry if this question has been posted and answered somewhere, but I
> have searched the postings and faqs and can find nothing on it.
> 
> I have a newish eMachine (low priced PC) with an AMD 333Mhz K2 that
> renders all my old povray scenes slower than my laptop with a 120Mhz
> Pentium (like 1/3 the speed rather than 3 times faster, as I would think
> it should). This very slow rendering performance occurs under both the
> Win98 and Mandrake Linux 6.0 OS installations on the eMachine so it does
> not appear to be a OS or software installation problem to me. (Perhaps
> the K2's L2 cache? but the laptop is older and only has smallish
> processor cache anyway.)
> 
> Any information would be greatly appreciated.

What kind of memory do you have plugged into it?  If it's DRAM instead
of SDRAM, you're seeling yourself short.

-- 
ICQ: 46085459

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Scott Sexton & David Lewis <2b### [at] cheerfulcom> wrote:
: I have a newish eMachine (low priced PC) with an AMD 333Mhz K2 that
: renders all my old povray scenes slower than my laptop with a 120Mhz
: Pentium (like 1/3 the speed rather than 3 times faster, as I would think
: it should). This very slow rendering performance occurs under both the
: Win98 and Mandrake Linux 6.0 OS installations on the eMachine so it does
: not appear to be a OS or software installation problem to me. (Perhaps
: the K2's L2 cache? but the laptop is older and only has smallish
: processor cache anyway.)

  The MHz amount tells very little about the real speed of the computer.
  I remember that some time ago a friend of mine had a 486DX4 overclocked
to 120MHz but it was a lot slower (in games, demos, etc) than my
486DX2 66MHz. The reason was that he had an ISA video card while I had a
VLB one. It's incredible how a slow video card can slow down a twice faster
computer so much.

  Of course the problem in your case can't be the video card, but the point
is that the MHz amount can be very misleading. Some poor component can make
the computer slower than other with half of MHz's.
  Perhaps you have a slow component slowing down the whole thing.
  Also I think that AMD has a quite slow FPU.

-- 
main(i,_){for(_?--i,main(i+2,"FhhQHFIJD|FQTITFN]zRFHhhTBFHhhTBFysdB"[i]
):5;i&&_>1;printf("%s",_-70?_&1?"[]":" ":(_=0,"\n")),_/=2);} /*- Warp -*/

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Nieminen Juha wrote:
> 
>   Of course the problem in your case can't be the video card, but the point
> is that the MHz amount can be very misleading. Some poor component can make
> the computer slower than other with half of MHz's.
>   Perhaps you have a slow component slowing down the whole thing.

>   Also I think that AMD has a quite slow FPU.

 Not that much !  It's MAYBE 10% slower in FPU than equivalent Intel,
but the memory management is better, so for Pov it's equivalent and
even sometimes better...
 There is a big problem with that computer !  (maybe it's the P120
who is wonderful, hehe !)

Fabien.

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Actually, POV depends pretty much on raw MHz. AMD's FPU might be a factor, but I
don't think the classic Pentium has a much better unit. Perhaps something
radical has been done in the BIOS, like turning off all processor caches. I
cannot think of any peripheral that could slow down POV by a significant amount.
How is the overall system performance? Does it swap a lot? Also, could you give
a benchmark time for POV (e.g. skyvase.pov @ 640x480 AA 0.3)

Margus

Nieminen Juha wrote:
> 
>   The MHz amount tells very little about the real speed of the computer.
>   I remember that some time ago a friend of mine had a 486DX4 overclocked
> to 120MHz but it was a lot slower (in games, demos, etc) than my
> 486DX2 66MHz. The reason was that he had an ISA video card while I had a
> VLB one. It's incredible how a slow video card can slow down a twice faster
> computer so much.
> 
>   Of course the problem in your case can't be the video card, but the point
> is that the MHz amount can be very misleading. Some poor component can make
> the computer slower than other with half of MHz's.
>   Perhaps you have a slow component slowing down the whole thing.
>   Also I think that AMD has a quite slow FPU.
> 
> --
> main(i,_){for(_?--i,main(i+2,"FhhQHFIJD|FQTITFN]zRFHhhTBFHhhTBFysdB"[i]
> ):5;i&&_>1;printf("%s",_-70?_&1?"[]":" ":(_=0,"\n")),_/=2);} /*- Warp -*/

Post a reply to this message

On Mon, 27 Sep 1999 14:48:22 +0300, Margus Ramst <mar### [at] peakeduee> wrote:

>Actually, POV depends pretty much on raw MHz. AMD's FPU might be a factor, but I
>don't think the classic Pentium has a much better unit.

  The earlier Pentium fpu was much better than both the units on the 486DX

486DX2-66 and my Skyvase.pov rendering time (640w x 480h, +a0.3) went from
32 minutes down to 15 minutes, which is more than the clock speed
improvement should show. AMD has greatly improved floating point performance
of its later K6 and K7 processors but I don't know how they compare with the
latest Pentium IIIs using POV-Ray.

  POV-Ray does work the fpu quite thoroughly. This is why most common
magazine benchmarks often don't apply if one is looking for the fastest
machine to run POV-Ray. They often use a test suite of programs that do not
perform as intensive floating point math as POV-Ray does. The converse if
also true - a machine that runs POV-Ray fast does not necessarily have the
good video performance that is required of fast 3d game play. Most test
suites take video performance into account but POV-Ray doesn't care if you
have a video card installed.

  The POVBench site at http://www.haveland.com/povbench/index.htm is a
database of user statistics on various machines. It might just be me but I
have a difficult time trying to make sense of so many entries. Many of these
personal computers are home-built, which may affect how fast they can render
Skyvase. Quite a few entries show that the submitted results use custom
compiled versions of POV-Ray. Without knowing exactly what their POV-Ray
source contained these results cannot be directly compared with others. I
mean, why would someone running Windows choose to compile their own
executable, unless they've modified the source?

-- 
Alan
http://www.povray.org - Home of the Persistence of Vision Ray Tracer

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John VanSickle wrote:

>
> What kind of memory do you have plugged into it?  If it's DRAM instead
> of SDRAM, you're seeling yourself short.
>

Thanks for your reply John. It's PC100 SDRAM.

Post a reply to this message

Scott Sexton & David Lewis wrote:
> 
> John VanSickle wrote:
> 
> >
> > What kind of memory do you have plugged into it?  If it's DRAM
> > instead of SDRAM, you're seeling yourself short.
> 
> Thanks for your reply John. It's PC100 SDRAM.

Assuming it's not faulty, it's not the problem.
-- 
ICQ: 46085459

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In article <37ef2389@news.povray.org>, Nieminen Juha <war### [at] cctutfi> wrote:
>Scott Sexton & David Lewis <2b### [at] cheerfulcom> wrote:
>: I have a newish eMachine (low priced PC) with an AMD 333Mhz K2 that
>: renders all my old povray scenes slower than my laptop with a 120Mhz
>: Pentium (like 1/3 the speed rather than 3 times faster, as I would think
>: it should). This very slow rendering performance occurs under both the
>: Win98 and Mandrake Linux 6.0 OS installations on the eMachine so it does
>: not appear to be a OS or software installation problem to me. (Perhaps
>: the K2's L2 cache? but the laptop is older and only has smallish
>: processor cache anyway.)
>
:
>  Also I think that AMD has a quite slow FPU.

This is what I was told about my Evergreen 586 upgrade to my PC. A while ago I 
rendered that simple glass that I made in sPatch... it took 7 hours to render 
(setting max_trace_level high was part of the problem) but I was told then 
that the AMD FPUs aren't that fast, however I never did hear back from that 
person if they knew if it was all AMDs or just the older 586s....

This is something I need to look into. When I replace this PC with a new one 
(I'm thinking about keeping the machine I got and run Linux on it, but anyway) 
I don't want to go out and buy a poor performace FPU if I'm going to continue 
to do stuff with POV (and I think I'm hooked now.... "you know you've been 
raytracing too long when you setup a seperate configuration and icon for the 
POVray Newsgroups).

PHIL

---------------------------------------------------

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Philip Bartol wrote:
> 
> This is what I was told about my Evergreen 586 upgrade to my PC. A while ago I
> rendered that simple glass that I made in sPatch... it took 7 hours to render
> (setting max_trace_level high was part of the problem) but I was told then
> that the AMD FPUs aren't that fast, however I never did hear back from that
> person if they knew if it was all AMDs or just the older 586s....
> 
> This is something I need to look into. 


I've just tried to find out about this. It's not easy to tell. AMD may be a bit
slower on FPUs but is more efficient on memory management and other things so
I've been told. The way I interpreted all information Intel is a few percent
faster but it's also more expensive (about 15% over here - with 450Mhz).
I opted for AMD but I don't think that was a 100% rational choice.

Remco

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