PC hardware advice

I'm interested in using RADIANCE for visual psychophysics. I've done a little bit of experimentation with an old laptop running Linux and now want to set up a dedicated RADIANCE system. The work I'm intending to carry out involves producing fairly large numbers of short animations so rendering speed is important but, as I don't want to spend large amounts of money, I'm thinking in terms of a consumer-type PC running Linux. Am I correct in assuming that rendering performance will be almost entirely determined by CPU and memory? I'd be glad of recommendations (specifically for using RADIANCE) about CPUs (basically Pentium 4 vs Pentium D) and memory (I assume 2G is ample - my scenes only contain 5 or 10 objects and one or two light sources). Some PC graphics cards (e.g. nVidia 6800) claim to handle more that 24 bits per pixel and hence support HDR imaging - will these improve the pixel-depth of my RADIANCE renders? The system will be calibrated with a spectroradiometer so we really can exploit improved colour resolution if it is there to be had!

many thanks,

Bob Kentridge
University of Durham

Radiance is a purely software renderer, so the ability of the graphics card
makes no difference. It's all CPU and memory. Memory is pretty cheap now,
so get a few gigs of it and you'll be happy.

I'd steer clear of the Pentium 4 - even Intel has ditched that failed
architecture. It has a very long pipeline, so any branch miss-prediction
is very expensive performance-wise. For their Pentium-M and new CPU's
Intel went back to the Pentium-III and the P6 core.

I'm an AMD fan myself, so I'd recommend an Athlon-64 or Opeteron.
I've heard that the new Intel 'Core' processors are doing pretty well,
even though they don't include the EM64T 64-bit extensions they copied
from AMD. They should do well, but definitely stay away from the Pentium 4!

bye

···

On Sun, 25 Jun 2006 14:38:09 +0100 Robert Kentridge <[email protected]> wrote:

I'm interested in using RADIANCE for visual psychophysics. I've done a
little bit of experimentation with an old laptop running Linux and now
want to set up a dedicated RADIANCE system. The work I'm intending to
carry out involves producing fairly large numbers of short animations so
rendering speed is important but, as I don't want to spend large amounts
of money, I'm thinking in terms of a consumer-type PC running Linux. Am
I correct in assuming that rendering performance will be almost entirely
determined by CPU and memory? I'd be glad of recommendations
(specifically for using RADIANCE) about CPUs (basically Pentium 4 vs
Pentium D) and memory (I assume 2G is ample - my scenes only contain 5
or 10 objects and one or two light sources). Some PC graphics cards
(e.g. nVidia 6800) claim to handle more that 24 bits per pixel and hence
support HDR imaging - will these improve the pixel-depth of my RADIANCE
renders? The system will be calibrated with a spectroradiometer so we
really can exploit improved colour resolution if it is there to be had!

Bob,

With 5-10 objects and 1 or two light sources, you probably won't need much RAM, actually. That is, unless each object has 10^6 triangles.

Nevertheless, I have compiled performance numbers sent in from many generous Radiance users at

http://mark.technolope.org/pages/rad_bench.html

I hope this helps you choose your CPU, and gives you hints for custom compile options.

Mark
[email protected]

···

On Sun, 25 Jun 2006, Robert Kentridge wrote:

I'm interested in using RADIANCE for visual psychophysics. I've done a little bit of experimentation with an old laptop running Linux and now want to set up a dedicated RADIANCE system. The work I'm intending to carry out involves producing fairly large numbers of short animations so rendering speed is important but, as I don't want to spend large amounts of money, I'm thinking in terms of a consumer-type PC running Linux. Am I correct in assuming that rendering performance will be almost entirely determined by CPU and memory? I'd be glad of recommendations (specifically for using RADIANCE) about CPUs (basically Pentium 4 vs Pentium D) and memory (I assume 2G is ample - my scenes only contain 5 or 10 objects and one or two light sources). Some PC graphics cards (e.g. nVidia 6800) claim to handle more that 24 bits per pixel and hence support HDR imaging - will these improve the pixel-depth of my RADIANCE renders? The system will be calibrated with a spectroradiometer so we really can exploit improved colour resolution if it is there to be had!

many thanks,

Bob Kentridge
University of Durham

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Radiance-general mailing list
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Hi Bob,

I'll chip into what Mark and Ian indicated. First off Mark's benchmark page is very useful, so do make sure to take a look. All of our production render servers are dual cpu AMD machines, these range from some of the first Athlon MP systems to more recent Opterons. We have not yet had the opportunity to look at any dual core systems, when we do AMD will be the top of the list. It has been many years since I really looked into it carefully. But initially the price/perfomance was pretty well in AMD's favor. You might want to pole more broadly among others doing scientific simulation (cfd for example) and see what kind of hardware they are using.

As far as graphics cards are concerned, this does not effect rendering speed, however it may have some impact on viewing the images, perhaps others can provide some good input on this particularly from the standpoint of calibration...? It might also be interesting to see if/when (and how much) the new HDR display devices will be available and what some of the hardware requirements are.

I would certainly suggest 2G of RAM, this should not increase the price very much. If you do not want to do a dual processor system, you can probably assemble a cheap system from parts for ~$800 or less (this asssumes a downloaded linux distribution such as Fedora Core), which I think is amazing compared to what I remember paying for our first production machines back in 1996 (~$4,000 per machine, ouch).

-Jack

Mark Stock wrote:

···

Bob,

With 5-10 objects and 1 or two light sources, you probably won't need much RAM, actually. That is, unless each object has 10^6 triangles.

Nevertheless, I have compiled performance numbers sent in from many generous Radiance users at

http://mark.technolope.org/pages/rad_bench.html

I hope this helps you choose your CPU, and gives you hints for custom compile options.

Mark
[email protected]

On Sun, 25 Jun 2006, Robert Kentridge wrote:

I'm interested in using RADIANCE for visual psychophysics. I've done a little bit of experimentation with an old laptop running Linux and now want to set up a dedicated RADIANCE system. The work I'm intending to carry out involves producing fairly large numbers of short animations so rendering speed is important but, as I don't want to spend large amounts of money, I'm thinking in terms of a consumer-type PC running Linux. Am I correct in assuming that rendering performance will be almost entirely determined by CPU and memory? I'd be glad of recommendations (specifically for using RADIANCE) about CPUs (basically Pentium 4 vs Pentium D) and memory (I assume 2G is ample - my scenes only contain 5 or 10 objects and one or two light sources). Some PC graphics cards (e.g. nVidia 6800) claim to handle more that 24 bits per pixel and hence support HDR imaging - will these improve the pixel-depth of my RADIANCE renders? The system will be calibrated with a spectroradiometer so we really can exploit improved colour resolution if it is there to be had!

many thanks,

Bob Kentridge
University of Durham

_______________________________________________
Radiance-general mailing list
[email protected]
http://www.radiance-online.org/mailman/listinfo/radiance-general

_______________________________________________
Radiance-general mailing list
[email protected]
http://www.radiance-online.org/mailman/listinfo/radiance-general

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