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On 14-Jul-08 9:14, Orchid XP v8 wrote:
> Chambers wrote:
>
>> Heh... while I never used the original model, most of the schools
>> where I lived used IIe's or later. As the article says, there are
>> *still* schools around that have labs full of them.
>
> Must be a regional thing... When I was at school, it was the BBC Micro -
> and nothing else!
>
Regional, as in 'country wide monopoly'.
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On 14-Jul-08 16:32, Warp wrote:
> Chambers <ben### [at] pacificwebguy com> wrote:
>> Orchid XP v8 wrote:
>>> But anyway, I was under the impression they used to be M68k-based, and
>>> then PPC, and then recently went to Intel Core 2.
>
>> From Wikipedia*: "Throughout the 1980s and much of the 1990s, the Apple
>> II was the de facto standard computer in American education; some of
>> them are still operational in classrooms today.
>
> There's no use in trying to convince him that Apple computers are or have
> ever been popular anywhere. He will never believe it, no matter how much
> evidence you pour to him.
No, he has vaguely heard of them, but it was before his time. While we
take an active interest in what happens in this world and how that came
about, he doesn't. I didn't believe it possible, until I met Andrew. Now
I have to admit that continuously living in the present is just as valid
and consistent as my way of life. You just have to remember when talking
to him that he has this strange behaviour.
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andrel <a_l### [at] hotmailcom> wrote:
> No, he has vaguely heard of them, but it was before his time. While we
> take an active interest in what happens in this world and how that came
> about, he doesn't. I didn't believe it possible, until I met Andrew. Now
> I have to admit that continuously living in the present is just as valid
> and consistent as my way of life. You just have to remember when talking
> to him that he has this strange behaviour.
Well, Apple computers being rather popular in some places *today* is
the present.
--
- Warp
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Orchid XP v8 wrote:
> But anyway, I was under the impression they used to be M68k-based, and
> then PPC, and then recently went to Intel Core 2.
That was the Mac series. The 8-bit computers that preceded the Mac used
the 6502 (or variants thereof).
Regards,
John
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John VanSickle wrote:
> Orchid XP v8 wrote:
>
>> I just wrote the assembly on a piece of paper, and when the program
>> was properly finished, it'd do the "assembling" part by hand. (I.e.,
>> open my dad's book and leaf through the op-code table.)
>
> Hand assembly was actually a common practice until 16-bit processors
> made this too troublesome;
Actually, it was pretty common before, too. Lots of machines designed to
be programmed in assembler had opcodes organized in a way that made it
easy to remember them and how to code them. If nothing else, it made
debugging via memory dumps easier. (You wonder why C supports octal?)
--
Darren New / San Diego, CA, USA (PST)
Helpful housekeeping hints:
Check your feather pillows for holes
before putting them in the washing machine.
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On 14-Jul-08 21:02, Warp wrote:
> andrel <a_l### [at] hotmailcom> wrote:
>>> There's no use in trying to convince him that Apple computers are or have
>>> ever been popular anywhere. He will never believe it, no matter how much
>>> evidence you pour to him.
>> No, he has vaguely heard of them, but it was before his time. While we
>> take an active interest in what happens in this world and how that came
>> about, he doesn't. I didn't believe it possible, until I met Andrew. Now
>> I have to admit that continuously living in the present is just as valid
>> and consistent as my way of life. You just have to remember when talking
>> to him that he has this strange behaviour.
> Well, Apple computers being rather popular in some places *today* is
> the present.
I don't think Apple ][ computers are much used anymore and that is the
one he was not familiar enough with to know which processor that used.
As I said above that is probably because they were already outdated when
he started using computers. I think there is absolutely no reason to
assume he dislikes them. So to be honest I don't see why you react this
way (I refer to the 3 lines above that I reincluded).
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>> Eventually I tired of this, and wrote my old assembler.
>
> The C64 had a cartridge port on the back end, and one fine company put
> out a cartridge called HESMon, which provided a mini-assembler, memory
> dump and editing, and so on.
Yes. I never did manage to afford one...
--
http://blog.orphi.me.uk/
http://www.zazzle.com/MathematicalOrchid*
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Orchid XP v8 wrote:
> Can somebody find out the typical MIPS and FLOPS for the following:
>
> - Commodore 64 (6510 @ ~1 MHz)
> - ZX Spectrum (Z80 @ 3.5 MHz)
> - Pentium I @ 66 MHz
> - Pentium II @ 233 MHz
> - Pentium III @ 500 MHz
> - Pentium IV @ 4.0 GHz
> - Intel Core 2 Quad @ 3.0 GHz
>
Get SETI@Home host statistics XML file. There is quite a variety of
computers there. <p_model> may or may not have the CPU speed. p_fpops and
p_iops have the floating point and integer benchmark results, respectively
(unit is operations per second, not million operations per second).
http://setiathome.berkeley.edu/stats/host.gz
(Warning: once uncompressed it's about 2GB, don't even *think* of using a
tree-based XML parser unless you have 8GB of RAM)
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Orchid XP v8 wrote:
> I didn't know much about algorithms back then. Give me a break! I was
> only 11...
Heh and that's why I don't like it when people here point at what I don't
know when in some cases I wasn't born when it went obsolete :P
When I was 11 I was doing Javascript. And I've yet to learn *any* kind of
assembly language.
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Nicolas Alvarez wrote:
> Orchid XP v8 wrote:
>
>> Can somebody find out the typical MIPS and FLOPS for the following:
>>
>> - Commodore 64 (6510 @ ~1 MHz)
>> - ZX Spectrum (Z80 @ 3.5 MHz)
>> - Pentium I @ 66 MHz
>> - Pentium II @ 233 MHz
>> - Pentium III @ 500 MHz
>> - Pentium IV @ 4.0 GHz
>> - Intel Core 2 Quad @ 3.0 GHz
>>
>
> Get SETI@Home host statistics XML file. There is quite a variety of
> computers there.
Clarification: you will NOT find a C64 in there.
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> Hand assembly was actually a common practice until 16-bit processors made
> this too troublesome; with at most 256 opcodes to remember (although the
> 6809[1] had prefix opcodes that made the following opcode take on a
> different meaning), many 8-bit assembly programmers were perfectly capable
> of reading and writing the opcodes directly from/to a memory listing.
With a RISC 32-bit processor it was pretty easy too. The instructions were
all 32-bit and all laid out in a similar way (first 5 bits for the
instruction code, next 3 for conditional flags, next 3 groups of 4 bits for
which registers to use, etc. The OS had a handy disassembly function
though, where you passed it the 32-bit opcode and it returned a string of
assembler, of course most programs/debuggers made use of this so you rarely
needed to actually decipher the bits.
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Nicolas Alvarez wrote:
> Clarification: you will NOT find a C64 in there.
Really? Nobody has modded their C64 to run this yet?
[You think I'm kidding???]
--
http://blog.orphi.me.uk/
http://www.zazzle.com/MathematicalOrchid*
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> - Commodore 64 (6510 @ ~1 MHz)
> - ZX Spectrum (Z80 @ 3.5 MHz)
> - Pentium I @ 66 MHz
> - Pentium II @ 233 MHz
> - Pentium III @ 500 MHz
> - Pentium IV @ 4.0 GHz
> - Intel Core 2 Quad @ 3.0 GHz
No idea about the processing power of those, but yesterday I saw a
Cray-1 supercomputer.
I say "supercomputer"... According to Wikipedia:
- 80 MHz clock.
- 160 MIPS theoretical peak.
- 136 MFLOPS typical.
- 250 MFLOPS peak (for heavily vectorised workloads).
- 8 MB RAM max.
- 5.5 tons.
- 115 kW for the basic system (NOT including cooling).
I'm having great difficulty finding numbers, but I'm told modern
computers are measured in multiple GFLOPS rather than MFLOPS. And
certainly they seem to hit tens of thousands of MIPS (although for
radically different instruction sets that's not a teffically meaningful
comparison).
It seems likely that my old laptop is more powerful that this 5.5-ton
Freon-cooled monster.
I'm now trying to find out if my laptop out-powers the Cray-2. I still
have a book somewhere claiming this to be "the world's most powerful
computer"...
--
http://blog.orphi.me.uk/
http://www.zazzle.com/MathematicalOrchid*
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Orchid XP v8 <voi### [at] devnull> wrote:
> No idea about the processing power of those, but yesterday I saw a
> Cray-1 supercomputer.
> I say "supercomputer"... According to Wikipedia:
> - 80 MHz clock.
> - 160 MIPS theoretical peak.
> - 136 MFLOPS typical.
> - 250 MFLOPS peak (for heavily vectorised workloads).
> - 8 MB RAM max.
> - 5.5 tons.
> - 115 kW for the basic system (NOT including cooling).
On the other hand, we are talking about 1976 here. With regular desktop
computers we were talking about KMIPS and KFLOPS and a few kB of RAM at
most.
--
- Warp
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On Mon, 14 Jul 2008 08:14:20 +0100, Orchid XP v8 <voi### [at] devnull> wrote:
>Chambers wrote:
>
>> Heh... while I never used the original model, most of the schools where
>> I lived used IIe's or later. As the article says, there are *still*
>> schools around that have labs full of them.
>
>Must be a regional thing... When I was at school, it was the BBC Micro -
>and nothing else!
When I was in school, we weren't even allowed to use calculators never mind have
access to a computer. The youth of today … :)
--
Regards
Stephen
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Warp wrote:
> On the other hand, we are talking about 1976 here. With regular desktop
> computers we were talking about KMIPS and KFLOPS and a few kB of RAM at
> most.
Oh, sure, not debating that. It's just impressive to see how far we've come.
People still talk about requiring a "Cray supercomputer" to perform a
given task. But it seems that the famous Cray-1 and Cray-2 were actually
far less powerful than a typical desktop today. (My dad saw me looking
at the Cray-1 and suggested using it just for POV-Ray. It seems to be
this would actually be a rather bad idea...)
--
http://blog.orphi.me.uk/
http://www.zazzle.com/MathematicalOrchid*
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>> Must be a regional thing... When I was at school, it was the BBC Micro -
>> and nothing else!
>
> When I was in school, we weren't even allowed to use calculators never mind have
> access to a computer. The youth of today … :)
Oh, this was at my first school. We used the computer for writing
things, and there was also a dragon-related "game" that was supposed to
be educational in some mannar... Hey, we were only little. ;-)
The school I spent most of my years at did not allow electronic devices
of any kind. We were also not allowed to watch TV because it was deemed
"too violent". (Except that the older kids were allowed to watch the
news - HOW IS THIS NOT VIOLENT???)
--
http://blog.orphi.me.uk/
http://www.zazzle.com/MathematicalOrchid*
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Orchid XP v8 wrote:
> People still talk about requiring a "Cray supercomputer" to perform a
> given task. But it seems that the famous Cray-1 and Cray-2 were actually
> far less powerful than a typical desktop today. (My dad saw me looking
> at the Cray-1 and suggested using it just for POV-Ray. It seems to be
> this would actually be a rather bad idea...)
There was somewhere out there a Cray-2 (I think) you could log into via
telnet and run apps. It had POV-Ray on it already, an older version (2.x
or maybe 3.0) I ran a basic scene from the samples and was surprised at
how long it actually took.
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Stephen wrote:
> When I was in school, we weren't even allowed to use calculators never mind have
> access to a computer. The youth of today … :)
Stephen, when you and I were in school, the slide rule was considered to
be cutting edge technology :-)
BTW Remind me to listen to the Kat when she suggests that going for a
drink with a bad back is not a good idea
John
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Mike Raiford wrote:
> There was somewhere out there a Cray-2 (I think) you could log into via
> telnet and run apps. It had POV-Ray on it already, an older version (2.x
> or maybe 3.0) I ran a basic scene from the samples and was surprised at
> how long it actually took.
Heh. One of the developers working on the Glasgow Haskell Compiler
commented off-hand that he had tried Haskell's STM implementation on a
machine with 128 CPUs and it had achieved a good speedup.
...OK, WHERE the HELL do you buy something that has 128 CPUs in it?? O_O
This information surely has a most direct relevance to all who worship
POV-Ray...!
--
http://blog.orphi.me.uk/
http://www.zazzle.com/MathematicalOrchid*
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Doctor John wrote:
> Stephen, when you and I were in school, the slide rule was considered to
> be cutting edge technology :-)
I saw a collection of slide rules yesterday... Of course, the really
"cutting edge" ones were the *spiral* rules. ;-)
I think the most amusing fact was my dad commenting "oh hey, that's the
model of slide rule we used to use at Glaxo. That brown one there..."
--
http://blog.orphi.me.uk/
http://www.zazzle.com/MathematicalOrchid*
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Orchid XP v8 wrote:
>
> ...OK, WHERE the HELL do you buy something that has 128 CPUs in it?? O_O
> This information surely has a most direct relevance to all who worship
> POV-Ray...!
>
Probably a custom order for an OEM.
Mmm.. 128+ rendering blocks in POV-Ray 3.7 ... Sign me up!
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Mike Raiford <mra### [at] hotmailcom> wrote:
> There was somewhere out there a Cray-2 (I think) you could log into via
> telnet and run apps. It had POV-Ray on it already, an older version (2.x
> or maybe 3.0) I ran a basic scene from the samples and was surprised at
> how long it actually took.
The speed of Crays don't come from CPU speed, but from havint a *lot*
of them (as well as fast memory buses, etc).
POV-Ray versions previous to 3.7 do not benefit from a Cray at all.
You get better speed by buying an old PC for $50.
Now, POV-Ray 3.7 is a completely different story.
--
- Warp
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Warp wrote:
> The speed of Crays don't come from CPU speed, but from havint a *lot*
> of them (as well as fast memory buses, etc).
>
> POV-Ray versions previous to 3.7 do not benefit from a Cray at all.
> You get better speed by buying an old PC for $50.
>
> Now, POV-Ray 3.7 is a completely different story.
According to Wikipedia, the Cray-1 does an average of about 136 MFLOPS,
but can peak up to 250 MFLOPS if the code is structured right.
I think in general most "supercomputers" only achieve peak performance
for very specific kinds of workload. Just grabbing the POV-Ray source
code and throwing it at a C compiler is *highly* unlikely to just happen
to produce the right kind of workload.
(As you say, both Cray-1 and Cray-2 work because they're very parallel -
they're vector-processing machines. POV-Ray isn't structured that way.
It could be, but it isn't at present.)
--
http://blog.orphi.me.uk/
http://www.zazzle.com/MathematicalOrchid*
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On Tue, 15 Jul 2008 17:29:08 +0100, Orchid XP v8 wrote:
> .OK, WHERE the HELL do you buy something that has 128 CPUs in it?? O_O
> This information surely has a most direct relevance to all who worship
> POV-Ray...!
http://tinyurl.com/67xzsp
Couldn't resist - but I do wonder if HPC clusters of Linux would work
with 3.7 from a parallel processing standpoint. Similar concept to what
Cray does/did.
Would be pretty cool if it did.
Jim
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Orchid XP v8 wrote:
> Nicolas Alvarez wrote:
>
>> Clarification: you will NOT find a C64 in there.
>
> Really? Nobody has modded their C64 to run this yet?
No, but there is one person who at least *tried* to run it on Windows 3.1
(using Win32s).
Workunits nowadays are long enough that a C64 would *never* make it in time
for the deadline. RAM usage will probably be a problem too. (I don't have
any real numbers handy, and the project is currently down so I can't try it
myself to see how long it takes).
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>> Really? Nobody has modded their C64 to run this yet?
>
> No, but there is one person who at least *tried* to run it on Windows 3.1
> (using Win32s).
>
> Workunits nowadays are long enough that a C64 would *never* make it in time
> for the deadline. RAM usage will probably be a problem too.
Yeah, I know. But you'd be surprised what some crazy nutters try to mod
their C64s to do... ;-)
--
http://blog.orphi.me.uk/
http://www.zazzle.com/MathematicalOrchid*
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Orchid XP v8 wrote:
>
> ...OK, WHERE the HELL do you buy something that has 128 CPUs in it?? O_O
> This information surely has a most direct relevance to all who worship
> POV-Ray...!
>
http://www.sgi.com/products/servers/altix/4000/
--
Eero "Aero" Ahonen
http://www.zbxt.net
aer### [at] removethiszbxtnetinvalid
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>> ...OK, WHERE the HELL do you buy something that has 128 CPUs in it??
>> O_O This information surely has a most direct relevance to all who
>> worship POV-Ray...!
>
> http://www.sgi.com/products/servers/altix/4000/
"Price: Ask a salesman."
So... the price depends on who you ask? x_x
--
http://blog.orphi.me.uk/
http://www.zazzle.com/MathematicalOrchid*
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Orchid XP v8 wrote:
>
> "Price: Ask a salesman."
>
> So... the price depends on who you ask? x_x
>
On that level, there ain't much salesmen to ask from. But I'd guess the
price is defined by what the machine actually will be, where it'll be
and how good coffees you offer to the salesman.
But darn, that should be capable of counting (512 pcs of dualcore
Itaniums, mmmm...).
--
Eero "Aero" Ahonen
http://www.zbxt.net
aer### [at] removethiszbxtnetinvalid
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On Tue, 15 Jul 2008 20:15:23 +0100, Orchid XP v8 wrote:
>>> ...OK, WHERE the HELL do you buy something that has 128 CPUs in it??
>>> O_O This information surely has a most direct relevance to all who
>>> worship POV-Ray...!
>>
>> http://www.sgi.com/products/servers/altix/4000/
>
> "Price: Ask a salesman."
>
> So... the price depends on who you ask? x_x
No, but pricing isn't always a simple thing with a complex setup.
Jim
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On 15-Jul-08 21:05, Eero Ahonen wrote:
> Orchid XP v8 wrote:
>>
>> ...OK, WHERE the HELL do you buy something that has 128 CPUs in it??
>> O_O This information surely has a most direct relevance to all who
>> worship POV-Ray...!
>>
>
> http://www.sgi.com/products/servers/altix/4000/
>
I might have posted this before, but the Mark Potse in this press
release:
http://www.sgi.com/company_info/newsroom/press_releases/2008/january/udm.html
was a PhD student of mine and when he is in the Netherlands we share a
room at work.
I did try to find a way to get SGI interested in getting POV compiled on
that Altix, I did not succeed yet. Perhaps I try again, this time with
the pretext that in a meeting in Munich next year I will organize a
track on Art and Scientific Visualization. BTW anyone working in science
here is invited to join that, I will do a formal announcement when I
have more details.
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Orchid XP v8 wrote:
> Yeah, I know. But you'd be surprised what some crazy nutters try to mod
> their C64s to do... ;-)
>
And you'd be surprised how much money some crazy nutters spend on computers
just to run distributed computing projects. I know somebody who bought a
PS3 just to run www.ps3grid.net on it.
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Orchid XP v8 wrote:
> I think in general most "supercomputers" only achieve peak performance
> for very specific kinds of workload. Just grabbing the POV-Ray source
> code and throwing it at a C compiler is *highly* unlikely to just happen
> to produce the right kind of workload.
That's one of the reasons the really big ones are custom designed for
the job they'll be running.
Sure, you could just network a bunch of Linux PCs in a Beowulf cluster,
or you could spec out the actual CPU speeds, RAM and network bandwidth
necessary to achieve optimum load on all components.
The first option is cheap, but you might have a very fast CPU sitting
and waiting for network traffic. Or, conversly, you could have a
network that's never fully utilized. Or you might end up running out of
RAM.
The second option is expensive, but ensures that everything you buy is
something you need, and that it will be fully utilized.
...Chambers
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> ...OK, WHERE the HELL do you buy something that has 128 CPUs in it?? O_O
> This information surely has a most direct relevance to all who worship
> POV-Ray...!
Saw a demo a while back where some dude had hooked up 3 PS3's to raytrace in
realtime at full HD resolution. That's 27 processor cores. I wonder how
fast it would be if someone ported POV to the PS3?
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scott wrote:
> Saw a demo a while back where some dude had hooked up 3 PS3's to
> raytrace in realtime at full HD resolution. That's 27 processor cores.
> I wonder how fast it would be if someone ported POV to the PS3?
Mmm, I'm seeing *a lot* of references to the PS3 in relation to high
performance computing. I know nothing about it, but from the sheer
weight of references, I'm guessing it's moderately well-equipted?
Actually, just porting POV-Ray to run on a GPU would probably yield some
interesting speedups. You'd have to radically restructure the program to
take advantage of the way GPUs work, but it should be quite fast...
--
http://blog.orphi.me.uk/
http://www.zazzle.com/MathematicalOrchid*
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> Mmm, I'm seeing *a lot* of references to the PS3 in relation to high
> performance computing. I know nothing about it, but from the sheer weight
> of references, I'm guessing it's moderately well-equipted?
There's a nice article on Wikipedia about the processor
http://en.wikipedia.org/wiki/Cell_processor
> Actually, just porting POV-Ray to run on a GPU would probably yield some
> interesting speedups. You'd have to radically restructure the program to
> take advantage of the way GPUs work, but it should be quite fast...
The problem is still floating point precision on the GPU - wait until they
get double precision throughout the pipeline and we'll begin to see some
interesting stuff. Also, as Warp always mentions, realistic multi-level
reflections and refractions are not simple at all (compared to the basic
"environment mapping" that almost every game uses).
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scott wrote:
>> Mmm, I'm seeing *a lot* of references to the PS3 in relation to high
>> performance computing. I know nothing about it, but from the sheer
>> weight of references, I'm guessing it's moderately well-equipted?
>
> There's a nice article on Wikipedia about the processor
>
> http://en.wikipedia.org/wiki/Cell_processor
Yeah, I'm reading about it now. (Hmm, I guess I'm not the only person
who still thinks 512 MB RAM is a lot. ;-)
>> Actually, just porting POV-Ray to run on a GPU would probably yield
>> some interesting speedups. You'd have to radically restructure the
>> program to take advantage of the way GPUs work, but it should be quite
>> fast...
>
> The problem is still floating point precision on the GPU - wait until
> they get double precision throughout the pipeline and we'll begin to see
> some interesting stuff.
nVidia GeForce 200 series is ment to offer double-precision when driven
using CUDA...
> Also, as Warp always mentions, realistic
> multi-level reflections and refractions are not simple at all (compared
> to the basic "environment mapping" that almost every game uses).
It's a completely different algorithm to be sure. The mathematics is
simple enough - it's figuring out how to make it efficient on real-world
hardware that's the hard part. ;-)
--
http://blog.orphi.me.uk/
http://www.zazzle.com/MathematicalOrchid*
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> Yeah, I'm reading about it now. (Hmm, I guess I'm not the only person who
> still thinks 512 MB RAM is a lot. ;-)
For a games console it's probably enough. What do you hold in RAM during a
game? All the 3D meshes and textures are on the GPU video memory only*.
Probably only the code, collision meshes, map data? And the PS3 OS is
vastly simpler than Windows, so I doubt that uses up much RAM.
* When you write a game under Windows, you must keep all the GPU data
mirrored in normal RAM, because if the user Alt-Tabs to a different 3D game,
you need to refill the GPU memory quickly (and not go through some long
load-from-disk process) when the user comes back to your app. On a games
console you don't need to do this, because (at least on the PS3) you have to
quit one game before you can go into another.
> It's a completely different algorithm to be sure. The mathematics is
> simple enough - it's figuring out how to make it efficient on real-world
> hardware that's the hard part. ;-)
There was a nice paper I read in a book a while back (one of the GPU gems
series I think), where some algorithm was explained for doing correct
multi-level reflections on the GPU. It was quite complex, involving
generating lots of cube-maps with depth and texture information and some
ray-tracing steps in a pixel shader. In the end they compared the output
with a real raytracer, and the results looked identical, but the GPU version
ran at about 10fps IIRC with something like 4 levels of reflection. The
real raytracer (Maya I think) was measured in minutes.
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>> Yeah, I'm reading about it now. (Hmm, I guess I'm not the only person
>> who still thinks 512 MB RAM is a lot. ;-)
>
> For a games console it's probably enough.
Well, judging by the number of PS3 games... ;-)
> What do you hold in RAM
> during a game? All the 3D meshes and textures are on the GPU video
> memory only*. Probably only the code, collision meshes, map data? And
> the PS3 OS is vastly simpler than Windows, so I doubt that uses up much
> RAM.
That's rather perverse though. Are you telling it you need "at least 2
GB RAM" to run M$ Office smoothly, but 1/8 of that is just fine for
running extremely intensive game software?
> * When you write a game under Windows, you must keep all the GPU data
> mirrored in normal RAM, because if the user Alt-Tabs to a different 3D
> game, you need to refill the GPU memory quickly (and not go through some
> long load-from-disk process) when the user comes back to your app. On a
> games console you don't need to do this, because (at least on the PS3)
> you have to quit one game before you can go into another.
Now that you mention it, if I Alt-Tab out of TF2, my PC locks up for
about 30 seconds. (As in, I get a black screen for 30 seconds.) Then
Windows comes up - possibly in the wrong resolution. Switching back to
TF2 is similarly slow. Go figure...
> There was a nice paper I read in a book a while back (one of the GPU
> gems series I think), where some algorithm was explained for doing
> correct multi-level reflections on the GPU. It was quite complex,
> involving generating lots of cube-maps with depth and texture
> information and some ray-tracing steps in a pixel shader. In the end
> they compared the output with a real raytracer, and the results looked
> identical, but the GPU version ran at about 10fps IIRC with something
> like 4 levels of reflection. The real raytracer (Maya I think) was
> measured in minutes.
As I understand it, technologies like CUDA allow you to run arbitrary
code on a GPU. So no need for convoluted trickery to convince the GPU
that your proplem is just like texture mapping, just feed it the actual
calculations you want it to do. (Of course, it runs arbitrary code, that
doesn't necessarily mean it runs it *fast*.)
Of course, CUDA is *only* for nVidia GPUs. (Wouldn't surprise me if ATi
had developed something similar.) I wonder if this will be like the old
3Dfx API where eventually everything gravitates towards a single API
that works for any GPU?
--
http://blog.orphi.me.uk/
http://www.zazzle.com/MathematicalOrchid*
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> That's rather perverse though. Are you telling it you need "at least 2 GB
> RAM" to run M$ Office smoothly, but 1/8 of that is just fine for running
> extremely intensive game software?
Well almost, I know that just double the PS3 RAM would be enough to run
Vista + Office smoothly. But then Vista does 842434 more things than the
PS3 OS does, so I think it's allowed to use up half a gig more if it wants
to.
> Now that you mention it, if I Alt-Tab out of TF2, my PC locks up for about
> 30 seconds. (As in, I get a black screen for 30 seconds.) Then Windows
> comes up - possibly in the wrong resolution. Switching back to TF2 is
> similarly slow. Go figure...
Of course it is up to the game writer how they handle Alt-Tabbing, and of
course it will depend how much RAM your machine has and how much of it is
used for other stuff. I imagine the mirror of the GPU data gets paged to
disc first, as it's not used until you Alt-Tab back to the app. But it
would be a silly game design if it had to reload and uncompress all the game
data each time you alt-tabbed back to the game.
> As I understand it, technologies like CUDA allow you to run arbitrary code
> on a GPU. So no need for convoluted trickery to convince the GPU that your
> proplem is just like texture mapping, just feed it the actual calculations
> you want it to do. (Of course, it runs arbitrary code, that doesn't
> necessarily mean it runs it *fast*.)
I suspect that the clever bit about CUDA is how it translates your arbitrary
code into operations that the GPU is capable of carrying out. And I also
suspect, that to get decent performance you need to have a pretty good
understanding of how the GPU actually works, and write your code
accordingly.
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>> That's rather perverse though. Are you telling it you need "at least 2
>> GB RAM" to run M$ Office smoothly, but 1/8 of that is just fine for
>> running extremely intensive game software?
>
> Well almost, I know that just double the PS3 RAM would be enough to run
> Vista + Office smoothly. But then Vista does 842434 more things than
> the PS3 OS does, so I think it's allowed to use up half a gig more if it
> wants to.
I just find it ironic that running Word requires massively more RAM than
running a bleeding-edge computer game, that's all.
> I suspect that the clever bit about CUDA is how it translates your
> arbitrary code into operations that the GPU is capable of carrying out.
Er, yuh. Definitely. ;-)
> And I also suspect, that to get decent performance you need to have a
> pretty good understanding of how the GPU actually works, and write your
> code accordingly.
Have you had a read of the CUDA manual? I don't know much about GPU
design, but reading this gave me a better idea of what this stuff works
internally...
--
http://blog.orphi.me.uk/
http://www.zazzle.com/MathematicalOrchid*
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On Tue, 15 Jul 2008 17:26:57 +0100, Doctor John <joh### [at] homecom> wrote:
>Stephen wrote:
>> When I was in school, we weren't even allowed to use calculators never mind have
>> access to a computer. The youth of today … :)
>
>Stephen, when you and I were in school, the slide rule was considered to
>be cutting edge technology :-)
So advanced I had to teach myself how to use one :)
>BTW Remind me to listen to the Kat when she suggests that going for a
>drink with a bad back is not a good idea
>
Was it the drink or going into work and travelling during the rush hour?
But then you are a man and listen to no one. :)
--
Regards
Stephen
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On Tue, 15 Jul 2008 17:30:50 +0100, Orchid XP v8 <voi### [at] devnull> wrote:
>
>I saw a collection of slide rules yesterday... Of course, the really
>"cutting edge" ones were the *spiral* rules. ;-)
Grom Google
About 1748 George Adams made spiral slide rules.
Cutting edge :)
--
Regards
Stephen
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> I just find it ironic that running Word requires massively more RAM than
> running a bleeding-edge computer game, that's all.
What you mean is, you don't understand why Vista needs more RAM than a
modern games console has to work properly. Did you ever think that a modern
desktop OS does vastly more than a games console does? Or that a modern OS
is designed to take advantage of hardware upgrades? (Vista is using 2.4GB
on this machine now with nothing much running, but I know that my CAD
software will open in a fraction of the time it did on XP - of course I want
MS to put in features like this).
Actually, I was surprised when I found this:
http://blogs.zdnet.com/Bott/?p=247
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scott wrote:
> What you mean is, you don't understand why Vista needs more RAM than a
> modern games console has to work properly. Did you ever think that a
> modern desktop OS does vastly more than a games console does?
Well let's examine that one.
I've only ever seen a PS3 in action once. I was using it to play a game
called "Call of Duty 4". Never heard of the game, but it looks amazing.
Only 10 years ago, a game like this would have been impossible. There
wasn't a computer on Earth powerful enough to run it. It's quite
impressive that it can even be done today, frankly.
On the other hand, Word just makes text appear on a screen, and lets you
edit it. (And change fonts and styles.) That was possible 20 years ago.
So why does it suddenly require so much hardware to achieve the same
thing as before? It's not like Word has any significant new features or
anything...
--
http://blog.orphi.me.uk/
http://www.zazzle.com/MathematicalOrchid*
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> So why does it suddenly require so much hardware to achieve the same
> thing as before?
Ermm, like I said, Word seems to use about 10MB here...
> It's not like Word has any significant new features or
> anything...
LOL
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Nicolas Alvarez wrote:
> When I was 11 I was doing Javascript. And I've yet to learn *any* kind of
> assembly language.
And that's why I have a big file of one-line-answer interview questions
testing the breadth of peoples' knowledge. Nevermore shall I be tasked
to assist someone implementing a network protocol who has never heard of
a state machine. :-)
--
Darren New / San Diego, CA, USA (PST)
Helpful housekeeping hints:
Check your feather pillows for holes
before putting them in the washing machine.
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Warp wrote:
> On the other hand, we are talking about 1976 here. With regular desktop
> computers we were talking about KMIPS and KFLOPS and a few kB of RAM at
> most.
On the gripping hand, one "mainframe" I programmed on (that was running
the entire K-12 school district, scheduling and grades and report cards
and payroll and such) could have been outrun by an Apple ][, if you
could get a 600 line-per-minute line printer hooked up to it. The same
kind of computer was running the local bank at the time. (Yeah, around
1976-1981 or so.) 32Kbytes of real live core memory, punched card
input, all that good stuff.
--
Darren New / San Diego, CA, USA (PST)
Helpful housekeeping hints:
Check your feather pillows for holes
before putting them in the washing machine.
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scott wrote:
> Saw a demo a while back where some dude had hooked up 3 PS3's to
> raytrace in realtime at full HD resolution.
I saw somewhere that someone took a stack of 8 PS3's to do <mumble>
(weather prediction? Nuclear simulations?) because that cost less *and*
was more powerful than a couple hour's time on the supercomputer he'd
been renting.
--
Darren New / San Diego, CA, USA (PST)
Helpful housekeeping hints:
Check your feather pillows for holes
before putting them in the washing machine.
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