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Cell Architecture Explained
IdiotOnMyLeft writes "OSNews features an article written by Nicholas Blachford about the new processor developed by IBM and Sony for their Playstation 3 console. The article goes deep inside the Cell architecture and describes why it is a revolutionary step forwards in technology and until now, the most serious threat to x86. '5 dual core Opterons directly connected via HyperTransport should be able to achieve a similar level of performance in stream processing - as a single Cell. The PlayStation 3 is expected to have have 4 Cells.'"
..it probably is.
was the ps2 the supercomputer it was said to be...?
the author goes on to suggest that cell workstations would smoke x86 counterparts.. but says at the same time that there probably wont be that many of them.
wtf? though in-between the lines you can read at the end that he also thinks a single g5-cpu workstation would 'smoke' x86's...
world was created 5 seconds before this post as it is.
Something that has always confused me in gaming consoles is that, despite incredibly powerful hardware (processors, graphical chips, etc.), the system developers seemingly always neglect to put in enough RAM for most games to perform to their potential. Many PC ports often have portions compromised due to the lack of RAM, and system speeds also suffer because of this.
Seeing how RAM is increasingly becoming cheaper, is it possible that new systems like the PlayStation3 might be able to provide RAM that actually allows games to reach their potential along with this new cell hardware?
I'll believe it when I see it. Sony made outrageous claims with the PS2 in the year or so before launch, I see no reason to believe this will be any different.
On paper an Emotion Engine was supposed to destroy everything, but achieving maximum throughput was difficult and other contraints such as I/O and memory hampered performance. Programmers had to learn a very different way of programming to make full use of the processor and it's two vector units.
A Cell might be a killer chip on paper, but real-world hardware with I/O latency and memory contraints will bring things down to a more reasonable level. Don't forget that multiprocessor programming is *hard*.
Hopefully, developing software for Cell chips will be easier then the early days of the PS2, Sony has already said as much a few months ago.
Quotes from article:
"GPUs will provide the only viable competition to the Cell but even then for a number of reasons I don't think they will be able to catch the Cell."
Did this guy forget that NVidia is designing the GPU for PS3? If Cell is so almighty, why does Sony uses NVidia GPU instead of using more Cells for graphic prosessing?
"There is another reason I don't think Nvidia or ATI will be able to match the Cell's performance anytime soon."
Of course, Cell based products won't be available anytime soon either. According to the current rumors, PS3 will be available in Japan in Spring 2006 and elsewhere in Autumn 2006. One and half years equals a generation in the GPU world...
I love this kind of articles where some future products are compared against current ones and declared as a clear winners...
"No Apps"? Try every single video game publisher in the world.
.. Sony or MSFT... I'd say its absolutely no contest. Sony would crush MSFT. They have better interface design, fewer conflicting platform goals, and they'll put a PS3 in your living room for a fraction of what MSFT could.
And besides, this isn't about "Office" style apps. Its about games, and more importantly: its about home media centers. I think the Windows MCE is going to have its rear-end handed to it by the PS3.
When you consider that a cell-based PS3 could have a computational power of *several times* a 3 GHz Pentium...
You have to ask, what's more likely: that Intel can get around IBM/Toshiba patents in time for Windows to conquer the living room with a faster box? (That's if they can even build a secure, stable OS with a decent UI). Or that Sony, now armed with the worlds fastest consumer-computing platform, an enormous user base and years of TiVO experience, will own the living room media center market.
If I had to bet on who builds a better media-center PC
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This sounds like a little PVM-cluster-on-a-chip. It also sounds like it's a pain to program and will, in the short term, suffer from the same problems that Intel's Itanium suffers from: it tries to push too much work on the compiler or software developer.
In the long term, it's nice that companies are exploring these kinds of architectures. It's not nice that they are trying to monopolize what are pretty straightforward architectural choices with patents. This may be a new CPU, but there is little that is new about having a bunch of fast processors interconnected via a reconfigurable network; these just happen to be on the same chip.
Well, perhaps "cool!" is not the correct response...
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Warning: Slashdot may contain traces of nuts.
a DBZ reference: "Part 4: Cell Vs the PC"
...Good lord I should have my anime viewers license revoked for knowing all that crap.
The 45 episode saga in which:
Bill Gates becomes a cyborg and summons the forces of evil.
A new Cell is constructed out of unsold Itaniums (Not to be confused with the Cell built by Sony, which is a friendly robot that is found out to be good. ( Until he is found out to be evil when the heroes notice he is under the control of the cyborg Bill Gates who has been behind the charade the entire time) and challenges the world to a rematch of earth shattering proportions
Second string characters have meaningless conversations that take up entire episodes
There is hilarious comic relief from common citizens in various towns as their cities crumble around them
Krillin dies
The dragon is summoned
Goku gets a haircut
One question which was not addressed fully in the article was how do you compile/test programs for this thing.
The potential of parallel architectures has never been in doubt since the early days of the Cray monsters - but how to compile code to use all the features efficiently has.
I don't believe that we see the full advantage of these types of architecture exploited without some similar break-through in software tools.
Mind you the hardware rocks...
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I'm sorry, but Sony can kiss my ass.
This is from the company that said the Playstation 2 would have Toy Story quality graphics, and be able to render FF8 quality FMVs in real time (thus making FMVs no longer required). It was essentially that bullshit hype that killed the Dreamcast... so yeah, now they're at it again.
Maybe I'll be proven wrong, but I doubt their system will be able to do anywhere near what they say it can in practical application.
I'm willing to believe that a 4.6 GHz chip with 8 ALUs and high bandwidth memory would be fast, but even in bulk, there's no way they can afford to put 4 of them in a sub-$500 game console.
I've been reading PR about the Cell for years, and nothing I've ever read has seemed even remotely plausible. Is there any objective information that even comes close to substantiating any of these claims?
While I tend to agree the Cell is an impressive architecture, this article is a steaming pile of B.S.
No cache for CPUs? A breakthrough? Hello! Both PSone and PS2 have the so-called scratchpad, which is what the Cell seems to have: a cache which has to be managed explicitly by the programmer. Breaking news: This is a royal pain in the ass. And calculating bandwidth when reading from this tiny scratchpads makes about as much sense as calculating the speed at which a x86 processor can execute MOV EAX, EBX.
Magically "the OS solves everything", and, in an obvious attempt to automatically get OSS-crowd support (is that "slashdot-trolling" or "slashdot-baiting"?) the triumph of Linux is predicted, because it's portable. Good luck getting the Linux kernel and GCC compiled, let alone running well on a massively parallel array of tiny CPUs without cache.
You have not read it. It will be on a specific class of tasks. It is similar to modern GPUs. They are faster then 10 opterons on a specific task.
Back to the article. The guy seems to understand hardware, but he does not understand shit about software. Once he got past the first 3 parts he started babbling. Linux on cell, so on, so fourth. If he just read his previous parts he should have hit himself on the head. The only type of linux this can run is mcLinux. There is no memory protection as such. So no Linux, no Windows past 2000, no MacOS past X, so on so fourth.
Similarly, it is all nice and well about cell software beasties making herds by themselves and cooperating on a task. I am going to be a spoilsport and ask a nasty question: Err.. What about a security model? Memory protection? Privilege model for communications? So on so fourth...
To continue on this, the power of a modern general purpose OS is the task switching. How long does it take to load and store the context of the vector processing units? Doing so requires moving their dedicated memory to main memory. This will take ages.
Overall, this is a design similar to Cray 1 initial design. Cray initial design smashed the IBM, DEC (and lesser fish) monopoly on big computing iron to bits. Unfortunately the next thing the people buying the Cray asked for was "can we share this resource between two people?". The answer was provided eventually, but by the time Cray could do all the nifty time sharing and memory management tricks necessary to do this its advantage was no longer phenomenal. And all people who could use Crays for single tasks with manual scheduling actually continued to use it that way. But it did not even dent the general purpose big iron market.
Baker's Law: Misery no longer loves company. Nowadays it insists on it
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Nicholas Blachford is an idiot. Do not read any of his articles. Just to give you the best of Nicholas, read his antigravity article and visit his web site:
;)
http://www.blachford.info/quantum/gravity.html
Also, look at the nose pictures of him
http://www.blachford.info/other/me.html
Seriously, the guy has burned most of his sane braincells.
For serious laugh, read his article series 'building the next generation' from osnews. I really got good laughs from that 4 part series.
Also, it didn't take long to spot a totally idiotic statement from todays slashdotted article:
> Parallel programming is usually complex but in this case the OS will look at the
> resources it has and distribute tasks accordingly, this process does not
> involve re-programming.
Here Nicholas misses the core problem of parallel programming. The program algorithms _always_ have to made parallel. The OS can't do it.
This part I agree with. His statements regarding abstraction are just flat out incorrect. Is this going to be programmed in assembly only? I think not...and if not there is significant abstraction involved. The thing that's closest to his point is that multiple *layers* of abstraction tend to add significant overhead. That doesn't mean that program-level abstractions do.
Once he got past the first 3 parts he started babbling. Linux on cell, so on, so fourth. If he just read his previous parts he should have hit himself on the head. The only type of linux this can run is mcLinux. There is no memory protection as such. So no Linux, no Windows past 2000, no MacOS past X, so on so fourth.
There is memory protection if the PU is in fact "something like a G5". IBM would have to be insane not include a MMU, and it has already stated that it's going to build workstations based on the Cell architecture.
All in all, interesting stuff...we'll see how it plays out. :-)
To continue on this, the power of a modern general purpose OS is the task switching. How long does it take to load and store the context of the vector processing units? Doing so requires moving their dedicated memory to main memory. This will take ages.
This, of course, depends on how many cells are in the box (with 8 vector units per cell) and how many tasks need vector units. The main purpose of the vector units in an interactive workstation will be multimedia processing. How many multimedia applications can you view at once? For me, the answer is one. The vector units may be useful for other things like engineering simulation and pattern matching, but once again how many different tasks using those features will be running at once? Plus if the processors are cheap enough to put 4 in a Playstation, one hopes the workstations will have 8 to 32 of them.
Overall, this is a design similar to Cray 1 initial design. Cray initial design smashed the IBM, DEC (and lesser fish) monopoly on big computing iron to bits. Unfortunately the next thing the people buying the Cray asked for was "can we share this resource between two people?". The answer was provided eventually, but by the time Cray could do all the nifty time sharing and memory management tricks necessary to do this its advantage was no longer phenomenal. And all people who could use Crays for single tasks with manual scheduling actually continued to use it that way. But it did not even dent the general purpose big iron market.
Two points. First, this is based on an already successful processor - the Power series. It already multitasks :-) and is used in a wide range of applications. Second, this will be a low-cost part. Crays were a super high-end system, which cost millions of dollars. Your analogy doesn't work.
Galileo: "The Earth revolves around the Sun!"
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There are two operating systems Microsoft have developed called Windows. DOS/Windows, the original one, was based on an x86 clone of CP/M that Microsoft bought. The first version, "Windows 1.0", was released in 1985. The last version, called "Windows Me", was released in 2000, IIRC. This OS was always x86-only, originally ran on archaic CPUs without memory protection and never supported full protected memory, symmetric multiprocessing or other (now) basic OS features.
The second OS developed by Microsoft that's marketed as Windows is Windows NT (now just called "Windows"). It was started in 1988, and never had any relation to DOS/Windows, except insofar as it can (to some extent) emulate it for compatibility reasons (including an x86 emulator on hardware that can't natively execute x86 code). Windows NT was developed on the MIPS platform, not the x86. The original plan had been to use the Intel i860 (an LIW architecture completely different from the x86) as the development platform, but the i860 hardware never met its promise, so MIPS was chosen instead.
The first version of Windows NT was released in 1993, and called "Windows NT 3.1" (3.1 was used for marketing reasons, since that was the latest version of DOS/Windows at the time). Like UNIX, it was mostly written in C, with assembly at the low level to handle hardware dependencies. At its release, Windows NT 3.1 ran on 32-bit MIPS (the development platform) and 32-bit x86 (the first port).
The second version of Windows NT (3.5) was released in 1994, and planned to add 64-bit Alpha (in a semi-crippled, 32-bit mode) and 32-bit PowerPC. However, IBM and Motorola ran into problems with the hardware (in part because of ongoing disagreements with Apple, who wanted to use their own, proprietary platform), so Windows NT 3.5 only added Alpha support. In 1995, after IBM and Motorola had managed to (mostly) sort out their problems (but with Apple declining to follow the IBM/Motorola PReP standard), the PowerPC port of Windows NT was completed, and released as version 3.51. At this point, the OS ran on MIPS, x86, Alpha and PowerPC.
In 1996, the user interface of Windows NT was upgraded to match the user interface of the popular 4.0 release of DOS/Windows (called Windows 95). Windows NT 4.0, which copied the user interface of DOS/Windows 4.0, ran on MIPS, x86, Alpha and PowerPC.
By the late 1990s, as Microsoft continued work on version 5.0 of Windows NT, the market had lost confidence in non-x86 systems for general-purpose PCs (apart from Apple Macs, which didn't follow the PReP standard, so couldn't run OSes ported to it, like AIX and Windows NT). As a result, Microsoft and the vendors of MIPS and PowerPC workstations agreed to cease development and marketing of NT 5.0 for those platforms. Windows NT 5.0 continued to be developed for the x86 and DEC Alpha architectures, into the beta releases.
DEC (which was taken over by Compaq) had continued to have hope for the Alpha as a general-purpose alternative to the x86, but financial difficulties led to the project being abandoned towards the end of the developent cycle for Windows NT 5.0 (marketed as "Windows 2000"). As a result, Windows NT 5.0, completed at the end of 1999, was the first version of NT that only ran on one platform (the x86).
A port of Windows NT 5.0 to the 64-bit Intel Itanium, including 64-bit versions of the Windows APIs (unlike the earlier Alpha port), was released in 2001, but only to select customers.
Windows NT 5.1 (marketed as "Windows XP) was also released in 2001, and again only ran on the x86, apart from another 64-bit limited release for Itanium (in 2002, IIRC).
Windows NT 5.2 (marketed as "Windows Se
No, this sort of architecture is a general trend towards paralellization. It is smart, and it is known to work, and I would expect some bright Sparc wise people to chime in and say "u-huh" and some SGI wise people to chime in and say "I've seen some of this before." The OS people are starting to move things in this direction, and I've heard that Darwin has had the asynchronous messaging type threading model for a while (RTFA: the article explicitly mentions Tiger's GPU leveraging techniques). If you have the head for it, try reading up on NUMA and compare that with SMP.
The math is simple. CPUs are CPUs, and anyone can make one that is the same speed as the competition, and if they do it second they can do it cheaper. The guy that can make 20 CPUs work like one CPU that does 20 times the work in a given time will win because he can always just throw more hardware at the problem. The SMP guys have to go back to the drawing board. In this case, the only way to beat-em is to join-em. Maybe doing the specific "Cell" computing design isn't it, but the ol' PC is dead. If these things start hitting the commodity price-points.
That's a big, fat IF. So, don't bet on it (yet), but it's even worse to ignore it.
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