Also, even with HyperThreading, the chips do NOT have 2 separate cores (although I suppose that could be done, in principle). It just allows software to think of them as two cores, and to schedule more than one process at a time.
The thing is, this usually works best when you have two separate types of task running concurrently on the processor, because they can (hopeully) take advantage of more execution units at one time. But, if you run two of the same scientific number crunching programs, on the hyper-threaded processor, they will both be competing for the floating point, and other, execution units at the same time. That competition has to be serialized by the chip, and the result may well be slower than if you just ran one process on the chip.
So, for this kind of computation, the hyper-threading may not be such a win (and it is probably marketed more for things like web-servers, where you might have a database program, and web content delivery program, both executing, and they may parallelize with each other a bit.
Well, first of all, I work at NASA as a researcher, doing numerical work (although I'm not a civil servant, and don't speak for them).
I agree that AltiVec is superior to SSE (ie. single precision), but you compared it to to SSE2, which is a bit apple-to-oranges (no pun intended, btw). If the G5 FPU is faster than current SSE2 at double precision, it just proves the well thought out design of the PowerPC architecture (and the unfortunate legacy of Intel's FPU instruction set, which is still a handicap even with SSE/SSE2, due to the need to mode switch). But SSE2 is still immature, and I expect compilers to improve, as well as chip implementations. Once they do, a more meaningful comparision can be made.
The Intel chips NEED stuff like SSE/SSE2 to achieve faster floating point speeds, whereas the PowerPC can get by without it, thanks to a much better FPU design, and thus, PowerPC makers will probably not spend the silicon to make a double precision SIMD instruction set anytime soon.
I stand by my claim that while most consumer and media software can get by with single precision, scientific computing (ie. large matrix calculations, to be blunt) quite often needs double precision (hell, you can get libraries that use 128 bit long doubles, these days), and will ultimately prefer SSE2. Scientists fuss with single precision SIMD simply because many of their applications can benefit so much from SIMD that it is worth the pain to use single precision (with proper conditioning and verification, etc.) Now that double precision SIMD is available, I can only predict they will want to jump to it, once tools for using it are there.
Granted, if Intel can't make a double precision SIMD unit that outperforms a double precision general FPU like the G5's, for matrix problems, then they don't deserve to design chips for scientific computing.:)
(which heavily benefits from Altivec, and Altivec is still king of the SIMD world, SSE2 isn't even close in performance.
Altivec is single-precision, SSE2 is double precision. The latter is invaluable for scientific computations of many types of matrix problems, and being wrong twice as fast is of little use.
Altivec is nice, for what it is meant for (mainly media type calculations, signal processing, etc.) But scientists will prefer SSE2.
Half Life, the original, was designed mainly as a single player experience. That is what the devleopers focused on. But they took great pains to ensure an active mod community could exist, and it did, and it helped make Half-life, and it's offshoots, the success that it was.
You could wait an extra three months while they add co-op play to Half-Life 2, or you can get it sooner, and in three months (or less), co-op play will exist from the mod community. The developers aren't saying they don't WANT co-op. Just that they know that they aren't necessarily the best ones to provide it. They want to provide (again) a ground breaking single player experience.
Well, I think his point was if we, the people, demand 'tit-for-tat' information awareness, then they, the government, might start to realize that it SHOULD be illegal. Ie., when push comes to shove, they will want to protect their privacy, and so will give us ours.
Mind you, that probably won't happen, but the point was this is a tactic we can use to at least TRY to have a government that protects our rights.
Yeah, but I'm saying that I scanned through the article twice, and didn't see the sentence you pointed out, and in particular, I didn't know you took issue (mainly) with the 6 dB figure as the "doubling" value. So, a link itself isn't always very helpful. One needs to supply some context.
But, anyway, I do thank you for pointing out my error. I'm happy to be a bit more clear on the specifics, in case I discuss the issue again.
Fair enough. I was being loose (and incorrect) with terms, since I originally only meant only to illustrate that doubling of sound intensity does not imply doubling of loudness, without getting too technical.
So, when talking in terms of SPL (or pressure level measurements), a 6 dB change represents a doubling or halving. (Note that the original poster mentioned 6 dBA, and I assumed that they were thinking in terms of the pressure level scale). However, I discussed power levels, and should have said 3 dB.
In terms of sound "intensity", or "energy", or "power", these all essentially refer to types of squared units (with "energy" being the most fundamental). And thus, a 3 dB change is a doubling or halving, on this scale.
Thus, to summarize, when talking about audio energy (squared pressure levels), 3 dB is doubling of energy, and 10 dB is doubling of "loudness".
However, when talking about audio pressure levels (ie. from a simple sound level meter), 6 dB is a doubling of pressure, and 20 dB would then be a doubling of "loudness".
Note that by these definitions, the sentence you quoted is also incorrect. It talked about doubling of power (ie. a 3 dB increase in power) effecting a 3 dB change in SPL, which is NOT a doubling of SPL (and is not a 'clearly audible increase'). Just goes to show how inconsistent these numbers can be when mixing terms. (I used to work more with sound measurement and recording, where 6 dB is a more commonly used value, as opposed to the 3 dB that is common with sound generation and electronics)
Amazingly, the very next Slashdot story is about audio sound, and the linked article has this paragraph in it:
"Because the decibel scale is logarithmic, with every 10 dB increase equivalent to a doubling of perceived sound (otherwise known as noise), dB drag racing enthusiasts create some seriously loud tones. (Another rule of thumb: All else being equal, every three dB of increased sound from a typical dB drag racing system requires a doubling of amplifier power.)"
Here the terms are very loosely used, talking about measured "sound" and "noise". The gist is what is important.
Finally, if you've read this far, I'll say that a response like "You're wrong. Read this.", with a link to a long article with only one or two sentences relevant to the point you are disputing (and without any information on what point you are disputing), is poor critique. You could have just said "You mean 3 dB, not 6 dB.", and then quoted from the article. And we could all go home happy. Just something to consider.
You know, this reminds me of the setup of a book by John Varley, called "The Ophiuchi Hotline". It starts off with us learning that humanity started receiving transmissions from space, in the direction of the Ophiuchus constellation. We started receiving it about 400 years prior, and have been decoding peices of it ever since. Of the amount that can be decoded and translated, we've learned about medicine, space travel, computers, etc. All kinds of amazing technology. No one knows who is sending it, or why.
But a repeating message has appeared, taking up more and more of the transmission. Our hero is summoned to a meeting where he learns that some of this repeating message has ben translated.
In summary, it reads: "Payment for service is overdue. Please remit immediately, or severe consequences will result."
The book plays out from this premise.
Let's hope we never have to deal with intergalactic IP issues.
And what exactly does that link have to say about human perception of loudness? It is about speaker efficiency, which is NOT what we were discussing. We are talking a subjective measure of loudness.
"loudness" in acoustical psychophysics is (grossly) defined like this:
Say I have the ability to measure the sound pressure intensity coming to your ears. ie. the "sound pressure level", which I can express with decibels. I play one tone and you listen to it. I then ask you to adjust the tone to be half as "loud". You do this. Thus, I have a relation between what you perceive is half as "loud", and what the sound pressure level is for that "loudness".
The "loudness" is purely subjective and perceptual. Different people will report different sound pressures as being half as loud, for the same starting value. But, averaged over lots of people, we get a representative curve.
The point I made is that although 6 dB represents a drop in the power level by half (or a halving of the intensity of the measured signal by a sound pressure meter), most people would require about a 10 dB reduction in intensity to report a halving of "loudness". ie. The slope of the curve is different. In fact, it is not non-linear, but most reference books on acoustics will have a curve showing perceived loudness to measured dB, for a standardized tone.
There is an adjusted scale, that compensates for this, that is called the "Sones" scale. So a halving of the value on the Sones scale, would be a halving of the loudness (for the "typical" person)
Sadly, things are even more complex than this, as frequency content also changes percevied loudness.
And, to back all this up, here is a usefull link I googled:
Actually, while a 6 dB change is a doubling or halving of signal power, it takes about 10 dB to hear a doubling of "loudness" (a measure of perception, ie. subjective). This is also a non-linear curve (so 10 dB change in a quiet sound will sound like more than a 10 dB change in a loud sound, if I remember correctly; wish I had my acoustics book with me.).
So, basically, while 6 dB change is significant, it is not nearly as good as a 10 dB change, in terms of perceived loudness.
We all know that some developers make minor changes to a release candidate before releasing the final (usually bugfixes). The information does have some relevance.
Maybe male characters are "worth" more because there is more demand for women wanting to have male characters, than men wanting to have female characters.
That's it. This article finally put me over the top with being fed up with michael. He is a prick of the world. I'm so glad he deigns to give us mere mortals lessons on marketing, since he clearly has what it takes to "understand" it.
Hey, michael, maybe "understanding marketing" is just the latest sign that you are in fact evil, and should kill yourself. Meanwhile, I'll form my own opinions, since I think I'm intelligent enough to do so. But, when I need a marketing lesson, I'll drop you a line for your insight.
Rant over, troll-mod away. But, all the other posters who've commented on michael's jack-assery over the years, have a point. michael himself finally convinced me they do.
GPL can be used in closed-source projects, as long as the binaries are not distributed to outside users. I would guess baby-mulching and A-Bomb dropping would call for in-house software development, so using GPLed code would be fine.
Music listeners? I was talking about movie DVDs. For music CDs, practically every CD burner comes with track ripping software. For music DVDs, I have no idea if the format is "cracked" or not.
All it takes is one $50 piece of software that runs on Windows to rip and re-encode the DVD for you, at the click of a button. And such software already exists.
Slashdot Mirror
Thanks for the correction. After I posted I felt a gnawing in my gut.
The PS2 emulates the PS1, because the entire PS1 (on a chip) is included within the PS2, to do the sound. It is not a software emulation.
Also, even with HyperThreading, the chips do NOT have 2 separate cores (although I suppose that could be done, in principle). It just allows software to think of them as two cores, and to schedule more than one process at a time.
The thing is, this usually works best when you have two separate types of task running concurrently on the processor, because they can (hopeully) take advantage of more execution units at one time. But, if you run two of the same scientific number crunching programs, on the hyper-threaded processor, they will both be competing for the floating point, and other, execution units at the same time. That competition has to be serialized by the chip, and the result may well be slower than if you just ran one process on the chip.
So, for this kind of computation, the hyper-threading may not be such a win (and it is probably marketed more for things like web-servers, where you might have a database program, and web content delivery program, both executing, and they may parallelize with each other a bit.
Well, first of all, I work at NASA as a researcher, doing numerical work (although I'm not a civil servant, and don't speak for them).
:)
I agree that AltiVec is superior to SSE (ie. single precision), but you compared it to to SSE2, which is a bit apple-to-oranges (no pun intended, btw). If the G5 FPU is faster than current SSE2 at double precision, it just proves the well thought out design of the PowerPC architecture (and the unfortunate legacy of Intel's FPU instruction set, which is still a handicap even with SSE/SSE2, due to the need to mode switch).
But SSE2 is still immature, and I expect compilers to improve, as well as chip implementations. Once they do, a more meaningful comparision can be made.
The Intel chips NEED stuff like SSE/SSE2 to achieve faster floating point speeds, whereas the PowerPC can get by without it, thanks to a much better FPU design, and thus, PowerPC makers will probably not spend the silicon to make a double precision SIMD instruction set anytime soon.
I stand by my claim that while most consumer and media software can get by with single precision, scientific computing (ie. large matrix calculations, to be blunt) quite often needs double precision (hell, you can get libraries that use 128 bit long doubles, these days), and will ultimately prefer SSE2. Scientists fuss with single precision SIMD simply because many of their applications can benefit so much from SIMD that it is worth the pain to use single precision (with proper conditioning and verification, etc.) Now that double precision SIMD is available, I can only predict they will want to jump to it, once tools for using it are there.
Granted, if Intel can't make a double precision SIMD unit that outperforms a double precision general FPU like the G5's, for matrix problems, then they don't deserve to design chips for scientific computing.
(which heavily benefits from Altivec, and Altivec is still king of the SIMD world, SSE2 isn't even close in performance.
Altivec is single-precision, SSE2 is double precision. The latter is invaluable for scientific computations of many types of matrix problems, and being wrong twice as fast is of little use.
Altivec is nice, for what it is meant for (mainly media type calculations, signal processing, etc.) But scientists will prefer SSE2.
Half Life, the original, was designed mainly as a single player experience. That is what the devleopers focused on. But they took great pains to ensure an active mod community could exist, and it did, and it helped make Half-life, and it's offshoots, the success that it was.
You could wait an extra three months while they add co-op play to Half-Life 2, or you can get it sooner, and in three months (or less), co-op play will exist from the mod community. The developers aren't saying they don't WANT co-op. Just that they know that they aren't necessarily the best ones to provide it. They want to provide (again) a ground breaking single player experience.
Actually, Darl McBride is Larry McVoy's brother. And Darl McBride is Larry McVoy's other brother.
Well, I think his point was if we, the people, demand 'tit-for-tat' information awareness, then they, the government, might start to realize that it SHOULD be illegal. Ie., when push comes to shove, they will want to protect their privacy, and so will give us ours.
Mind you, that probably won't happen, but the point was this is a tactic we can use to at least TRY to have a government that protects our rights.
Yeah, but I'm saying that I scanned through the article twice, and didn't see the sentence you pointed out, and in particular, I didn't know you took issue (mainly) with the 6 dB figure as the "doubling" value. So, a link itself isn't always very helpful. One needs to supply some context.
But, anyway, I do thank you for pointing out my error. I'm happy to be a bit more clear on the specifics, in case I discuss the issue again.
Fair enough. I was being loose (and incorrect) with terms, since I originally only meant only to illustrate that doubling of sound intensity does not imply doubling of loudness, without getting too technical.
So, when talking in terms of SPL (or pressure level measurements), a 6 dB change represents a doubling or halving. (Note that the original poster mentioned 6 dBA, and I assumed that they were thinking in terms of the pressure level scale). However, I discussed power levels, and should have said 3 dB.
In terms of sound "intensity", or "energy", or "power", these all essentially refer to types of squared units (with "energy" being the most fundamental). And thus, a 3 dB change is a doubling or halving, on this scale.
Thus, to summarize, when talking about audio energy (squared pressure levels), 3 dB is doubling of energy, and 10 dB is doubling of "loudness".
However, when talking about audio pressure levels (ie. from a simple sound level meter), 6 dB is a doubling of pressure, and 20 dB would then be a doubling of "loudness".
Note that by these definitions, the sentence you quoted is also incorrect. It talked about doubling of power (ie. a 3 dB increase in power) effecting a 3 dB change in SPL, which is NOT a doubling of SPL (and is not a 'clearly audible increase'). Just goes to show how inconsistent these numbers can be when mixing terms. (I used to work more with sound measurement and recording, where 6 dB is a more commonly used value, as opposed to the 3 dB that is common with sound generation and electronics)
Amazingly, the very next Slashdot story is about audio sound, and the linked article has this paragraph in it:
"Because the decibel scale is logarithmic, with every 10 dB increase equivalent to a doubling of perceived sound (otherwise known as noise), dB drag racing enthusiasts create some seriously loud tones. (Another rule of thumb: All else being equal, every three dB of increased sound from a typical dB drag racing system requires a doubling of amplifier power.)"
Here the terms are very loosely used, talking about measured "sound" and "noise". The gist is what is important.
Finally, if you've read this far, I'll say that a response like "You're wrong. Read this.", with a link to a long article with only one or two sentences relevant to the point you are disputing (and without any information on what point you are disputing), is poor critique. You could have just said "You mean 3 dB, not 6 dB.", and then quoted from the article. And we could all go home happy. Just something to consider.
You know, this reminds me of the setup of a book by John Varley, called "The Ophiuchi Hotline". It starts off with us learning that humanity started receiving transmissions from space, in the direction of the Ophiuchus constellation. We started receiving it about 400 years prior, and have been decoding peices of it ever since. Of the amount that can be decoded and translated, we've learned about medicine, space travel, computers, etc. All kinds of amazing technology. No one knows who is sending it, or why.
But a repeating message has appeared, taking up more and more of the transmission. Our hero is summoned to a meeting where he learns that some of this repeating message has ben translated.
In summary, it reads: "Payment for service is overdue. Please remit immediately, or severe consequences will result."
The book plays out from this premise.
Let's hope we never have to deal with intergalactic IP issues.
And what exactly does that link have to say about human perception of loudness? It is about speaker efficiency, which is NOT what we were discussing. We are talking a subjective measure of loudness.
d /l oud.html#c2
d /p hon.html#c2
"loudness" in acoustical psychophysics is (grossly) defined like this:
Say I have the ability to measure the sound pressure intensity coming to your ears. ie. the "sound pressure level", which I can express with decibels. I play one tone and you listen to it. I then ask you to adjust the tone to be half as "loud". You do this. Thus, I have a relation between what you perceive is half as "loud", and what the sound pressure level is for that "loudness".
The "loudness" is purely subjective and perceptual. Different people will report different sound pressures as being half as loud, for the same starting value. But, averaged over lots of people, we get a representative curve.
The point I made is that although 6 dB represents a drop in the power level by half (or a halving of the intensity of the measured signal by a sound pressure meter), most people would require about a 10 dB reduction in intensity to report a halving of "loudness". ie. The slope of the curve is different. In fact, it is not non-linear, but most reference books on acoustics will have a curve showing perceived loudness to measured dB, for a standardized tone.
There is an adjusted scale, that compensates for this, that is called the "Sones" scale. So a halving of the value on the Sones scale, would be a halving of the loudness (for the "typical" person)
Sadly, things are even more complex than this, as frequency content also changes percevied loudness.
And, to back all this up, here is a usefull link I googled:
http://hyperphysics.phy-astr.gsu.edu/hbase/soun
And this one on sones:
http://hyperphysics.phy-astr.gsu.edu/hbase/soun
Actually, while a 6 dB change is a doubling or halving of signal power, it takes about 10 dB to hear a doubling of "loudness" (a measure of perception, ie. subjective). This is also a non-linear curve (so 10 dB change in a quiet sound will sound like more than a 10 dB change in a loud sound, if I remember correctly; wish I had my acoustics book with me.).
So, basically, while 6 dB change is significant, it is not nearly as good as a 10 dB change, in terms of perceived loudness.
Yeah. Without the Challenger, who knows when we can launch the Hubble telescope?
We all know that some developers make minor changes to a release candidate before releasing the final (usually bugfixes). The information does have some relevance.
Maybe male characters are "worth" more because there is more demand for women wanting to have male characters, than men wanting to have female characters.
If Bill ever collects on Social Security, it might make front page news (well, front Slashdot page news, anyway).
What is that checkpoint for anyway? Immigration? Drunk driving? (it has been there too long for "homeland security")
Policae are like anything else? It is the rotten 98% that spoil it for the other few good ones.
Right. Movie distribors should be subsidizing the switch to digital (since it has the potential to save them so much on distribution costs).
:)
Maybe Fedex or whatever courier service they use, is lobbying them against doing so.
That's it. This article finally put me over the top with being fed up with michael. He is a prick of the world. I'm so glad he deigns to give us mere mortals lessons on marketing, since he clearly has what it takes to "understand" it.
Hey, michael, maybe "understanding marketing" is just the latest sign that you are in fact evil, and should kill yourself. Meanwhile, I'll form my own opinions, since I think I'm intelligent enough to do so. But, when I need a marketing lesson, I'll drop you a line for your insight.
Rant over, troll-mod away. But, all the other posters who've commented on michael's jack-assery over the years, have a point. michael himself finally convinced me they do.
Why in hell does that site need to set a cookie?
*Ford* was advertising in the middle of Schindler's List? That takes some fuckin' balls.
GPL can be used in closed-source projects, as long as the binaries are not distributed to outside users. I would guess baby-mulching and A-Bomb dropping would call for in-house software development, so using GPLed code would be fine.
Music listeners? I was talking about movie DVDs.
For music CDs, practically every CD burner comes with track ripping software. For music DVDs, I have no idea if the format is "cracked" or not.
All it takes is one $50 piece of software that runs on Windows to rip and re-encode the DVD for you, at the click of a button. And such software already exists.