Cray CTO: Linux clusters don't play in HPC 435
jagger writes "Linux clustering was touted as the next big thing by many vendors last week at ClusterWorld Conference & Expo 2004. But supercomputer vendor Cray Inc. scoffed at the notion of putting Linux clusters in the high-performance computing (HPC) category. "Despite assertions made by Linux vendors, a Linux cluster is not a high performance computer," said Dr. Paul Terry, CTO of Cray Canada."
Marketing (Score:5, Insightful)
While Paul Terry makes some good points, in his statements, including the partial quote from the post, "Despite assertions made by Linux vendors, a Linux cluster is not a high performance computer, said Dr. Paul Terry, CTO of Cray Canada. "At best, clusters are a loose collection of unmanaged, individual, microprocessor-based computers."
Remember to take this with a grain of salt. The inflammatory nature of the comment is nothing more than a marketing ploy to increase visibility of, and sell, the new Cray XD1
Re:Marketing (Score:5, Funny)
I'm sure Paul Terry is nothing more han a loose collection fo unmanaged, individual human cells too. But I'm sure, with hard work and love, he can become a _real_ boy! Lets all have a hug.
Help me here... (Score:3, Insightful)
I know I keep coming back to Virginia Tech, but isn't all those G5's linked together to make the 3rd fastest supercomputer itself a cluster? Or is it considered something else?
And if it IS considered a cluster, then why wouldn't a Linux based (along with the *BSD based G5s) be able to make a fast supercomputer?
If so, then what Paul Terry is spouting is just FUD and marketing to help sell his product, yes?
Just wondering.
Re:Help me here... (Score:5, Insightful)
So depending on the task at hand, the cluster might perform very well, or perhaps a little less well. Cray supercomputers are a big number of processors all in the same machine, and more importantly all sharing the same memory. Each processor has the same delay to access any memory content.
The argument in favor of clusters, however, is that it's still cheaper to throw more computers in than to buy a Cray that would perform the same task in less time.
In the end, there's a lot of marketing involved in all of this...
Hope this helps (and that I'm not completely wrong!),
Maan
Re:Help me here... (Score:5, Interesting)
So depending on the task at hand, the cluster might perform very well, or perhaps a little less well.
Surely what you meant to say is that, depending on the task at hand, a cluster might perform very well, or perhaps perform attrociously. :-)
Clusters tend to work well when the various nodes don't need to communicate very often but you need lots of cycles for the subtasks, while dedicated supercomputers tend to perform very well in tasks requiring vast amounts of internode communications bandwidth along with large numbers of cycles. If you need vast bandwidth and relatively low numbers of cycles, your pricepoint is likely a mainframe. And if you don't need either, you get a cheap desktop machine.
Certain problems parallelize well on a cluster ... others don't. Some don't parallelize at all, and a cluster won't do you a darn bit of good. The different machines are designed for different uses ... and one should be careful not to push a "one size fits all" solution. The Cray guy clearly got it wrong on that point, and likely knows it, but he was marketting, not teaching a course in choosing hardware for the task at hand.
Re:Help me here... (Score:5, Informative)
http://www.ibiblio.org/pub/Linux/docs/HOWTO/oth
has a great explanation using a grocery story analogy that makes it really easy to understand what kind of tasks will work well and what kind will suck. And unlike the cheerleaders that have been showing up since clusters became a big business is very balanced about it.
Still worth reading.
Re:Help me here... (Score:5, Informative)
Format links like this: <a href="http://somelink">link text</a>
It takes virtually no extra time and we don't have to trim the fucking slashcode spaces.
Oh, and here's [ibiblio.org] the link.
Re:Help me here... (Score:3, Interesting)
Sure, this reduces peak efficiency. I think on the VT cluster it was in the 50-60% range (I could Google search but I'm lazy... shoot me)... that is, the total performance is about
Re:Help me here... (Score:3, Informative)
With problems that can be split up into hundreds or thousands of more-or-less independent subtasks, a cluster is the way to go. But for problems that can't be divided up like that, a smaller system with a few very tightly coupled extremely fast vector processors, like what Cray s
Valid Question, then (Score:3, Interesting)
At what price point does the Cray XD1 come in? While huge clusters are (supposedly) cheap individual computers -- I would argue that G5s are not inherantly cheap -- how many G5s that make up the Virginia Tech cluster would you have to get to before you've paid for a Cray XD1?
I mention this because the article implies that Cray is planning on selling the XD1s at a price point cheaper than equivelant clusters. If they succeed at making the XD1 cheap enough, then it may be more cost effective to [[ effectiv
Re:Help me here... (Score:3, Interesting)
Re:Marketing (Score:3)
Re:Marketing (Score:5, Informative)
As for research, it's more a case of researchers doing the old "Damn, I'll have to make do with this". And Origin and Altix systems are still selling well in the research market.
And don't forget, Cray is backed by US government departments such as the NSA. The X1 received a lot of such support, which Cray even admits themselves: http://www.cray.com/products/systems/x1/
Re:Marketing (Score:5, Insightful)
If you need to access remote memory in a super cluster, such as the ones mentioned above, you take a BIG hit in terms of performance. Think about running from swap space vs. running an application out of memory and you'll be on the right track. In these sorts of situations a system like that Cray down in slot 19 could easily beat out nearly anything above it on that list (almost all of which are superclusters except for Earth Simulator at #1).
As others have mentioned, the guy was clearly talking from a marketing standpoint rather than a "chose the best solution for the job" standpoint, however what he said isn't entirely without value. There are a lot of tasks out there where that Big Mac supercluster that people keep touting would suck-ass. Even with their high-bandwidth, low-latency infiniband interconnect you're still looking at a good 3 orders of magnitude lower performance for remote memory vs. local memory.
Yeah, but imagine... (Score:3, Funny)
Seymour Cray (Score:5, Funny)
"If you were plowing a field, which would you rather use? Two strong oxen or 1024 chickens?"
Maybe he meant penguins?
Re:Seymour Cray (Score:3, Insightful)
"If you were building an ants nest, which would you rather use? 1024 Ants or a Bulldozer?"
Perhaps he shouldn't be comparing plowing fields to high performance computing.
Re:Seymour Cray (Score:4, Funny)
Obligatory (Score:4, Funny)
Re:Obligatory (Score:3, Funny)
Re:Seymour Cray (Score:5, Insightful)
The analogy now would be more like:
Re:Seymour Cray (Score:4, Insightful)
If you are plowing fields, use the bull.
If you are making eggs, use the chickens.
This isn't a one-size-fits-all world any more. Only those deluded enough to think that Windows should be the world's standard desktop think otherwise.
Re:Seymour Cray (Score:3, Funny)
Re:Seymour Cray (Score:5, Funny)
And when you're done plowing, you can fry 'em up all tasty.
Re:Seymour Cray (Score:3, Funny)
But only if they're GNU/Chickens....
Re:Seymour Cray (Score:5, Funny)
Personally, I'd prefer a John Deere 6003 Series [deere.com].
Re:Seymour Cray (Score:3, Insightful)
Re:Seymour Cray (Score:5, Funny)
Re:Seymour Cray (Score:5, Funny)
Re:Seymour Cray (Score:3, Insightful)
Re:Seymour Cray (Score:5, Funny)
Re:Seymour Cray (Score:3, Funny)
Re:Seymour Cray (Score:5, Funny)
When Seymour Cray made that statement, he was probably pointing out the difference between his he-man vector processors vs. clusters of the wimpy microprocessors of old.
After reading the article, it seems that this new Cray is powered by a bunch of the exact same AMD microprocessors that a cluster of Linux boxes would use. So what they have now is more like an ox-shaped sack stuffed with chickens.
Business or science? (Score:2, Interesting)
Dr. Terry's assertions remind me of a Seymour Cray quote I had as my
I'm not picking a side, it just seems interesting that the Cray CTO would echo Seymour's thoughts. I guess it's for business and marketting reasons though, sadly.
Re:Business or science? (Score:3, Funny)
"Here he comes, get ready boys! Cluck cluck cluck cluck cluck, here chickey chikcey, Haw Haw Haw!", etc.
BTM
CTO of Cray? (Score:2, Interesting)
Todays headlines... (Score:4, Funny)
And in other news... (Score:5, Insightful)
So all those supercomputing labs that use Linux clustering (that invented Linux clustering, even) have been wasting their time?
Re:And in other news... (Score:5, Insightful)
The problem for these guys is that, in terms of real world enterprise usage, not everybody needs the features they offer. My business doesn't need the easy management and clustering features in IIS, heck the website hasn't been updated in months and this time kast year nobody even knew which machine it ran on. We don't need the task scheduling, file striping, data transformation, replication or XML features of Orcale. In fact, we only need a tiny sliver of the possible functionality of these great products...but we're unable to pay a sliver of the price. With OSS ramping up its feature set daily, for a lot of companies with our needs it makes more sense to train a guy on Linux than to drop five digits on Windows Server 2003 and SQL Server.
As for supercomputing...well, a cluster is NOT a mainframe. They're two similar, but different things, with the main difference being the databus. If your task is to perform a lot of calculations on a trivial dataset, clustering is the way to go. If your task is to perform a few calculations on a massive dataset, you want a mainframe. The mainframe is simply more efficient at processing massive inputs and providing massive outputs because it was designed to efficiently pass data between processors -- give the same dataset to a cluster and most of your time is wasted negociating the network.
Of course, these days networking is so fast that a cluster will probably do for most of the things people used to do on mainframes...but a cluster is still best for tasks which are easy to split apart and process in pieces.
Re:And in other news... (Score:3, Insightful)
Oracle disclaim MySQL and PostgreSQL as "toy databases"
Yup kid and for very good reasons. Take sometime off from paying with your toys and regiter at OTN to learn about what Oracle 8i and 9i database are capable of. You'd literally blow your head off if you see what their Apps are capable of.
For a start, consider 4 page long nested views that pull data from more than 40 tables where some contain upwards of million rows. And these views are accesed thousands of times a day in their apps.
Here is an
Re:And in other news... (Score:2)
...the same ole FUD? (Score:3, Interesting)
"Anyone using the terms 'zealot' or 'FUD' in a Slashdot discussion is immediately declared the loser of the thread and discussion stops at that point".
Of course I'm force to break my own corollary to make this point.
But to call me a "Linux zealot spouting FUD" (and excuse me for paraphrasing your lucid comment) because I mock a commercial vendor who says that the free alternative is no competition... WTF?
As it happens: I have
Re:...the same ole FUD? (Score:3, Interesting)
True. But I spout what are called "stealth opinions", being understated (or even unstated) makes them harder to criticize, and I have the advantage of being able to change opinion in mid-spout to dodge the zealots.
Are too (Score:5, Interesting)
I guess that the simple problem is just that the algorithm applied is usually not suitable for massively parallel computing.
Re:Are too (Score:3, Insightful)
Ya beat me to that one. I won't post it because it would be modded redundant, but I would have mentioned Google also.
Re:Are too (Score:5, Insightful)
Many other computing problems don't decompose nearly so nicely. So there are certainly problems that probably won't see more than 8% of peak performance. If you were particularly inclined you could probably invent a problem that had to be done serially, leaving percent of peak performance equal to what percent of your cluster one box was. Cray is right to that extent and if you're solving a problem that falls into the category of not easily parallelized then perhaps one of their machines is the better tool for the job. But, like you mention there are instances where the cluster is a great tool and cost effective to boot.
Heck, ever check out some of the faster interconnects like Myrinet? They're insane and exist because fast ethernet just doesn't cut it in some places. Just using a slow interconnect is enough to bring real performance down below theoretical peak. Luckily for Pixar off the shelf fast or gigabit ethernet is likely enough.
Anyway, use the best tool available. If your problem falls into the category of trivially parallelizable like rendering a movie is then don't bother wasting your money on a Cray. If your problem isn't suited to a cluster, however, then maybe a cluster isn't the right answer. If you have a big problem that needs serious computation take the time to figure out what you need before taking a marketing drone's spiel for gospel in your situation.
Re:Are too (Score:4, Interesting)
Message passing is the biggest issue with such solvers, and in a way, cray was absolutely right about Linux, although misleading. There are some tests going on now with a modified Linux kernel for doing true HPC, and it's been done in the past (I know, I've used it). Things like disk swapping pretty much immediately disqualifies you for high performance computing. It has its place of course, such as trivially parallelizable codes is one example (Pixar).
Myrinet was out before Gbit ethernet was really available, and also has some nifty routing capabilities. And since the bottleneck for HPC is usually message passing, high performance computing will better realize its theoretical performance as the communication speed catches up to the processor speed.
But, to Cray's discredit, making a blanket statement that Linux can't do HPC is like saying Macintoshes can't do HPC. [top500.org]
Re:Are too (Score:4, Informative)
Raytracing is sometimes referred to as "embarrasingly parallel", because of this.
Mathematical dependencies is the real destroyer of parallelism. Any situation where the next calculation depends on the result on the previous is a typical serial calculation that would do badly on any super-computer and might as well be run on a single single scalar processor like the Athlon or P4.
VA Cluster yet to be used (Score:4, Insightful)
The 1100 node Apple G5 cluster in virginia has yet to run any real scientific code. So far it has only ran benchmarks.
Re:VA Cluster yet to be used (Score:4, Informative)
The cluster remains, they have not shut it down and were swapping out individual racks for the upgrade.(something like one rack of X-serves is three racks of towers.
I don't think it's been published that they have or haven't ran any data besides benchmarks.
What do you expect him to say? (Score:3, Insightful)
I am not saying Cray isn't worth it, but there is something to be said on replacing/fixing your supercomputer with over the counter parts.
Re:What do you expect him to say? (Score:3, Insightful)
Also remember, these gu
So what DOES play in HPC? (Score:3, Interesting)
Sure... (Score:5, Insightful)
"Despite assertions made by Toyota salesmen, a Lexus sedan is not a luxury car," said Bill Taylor, CEO of Mercedes-Benz.
Re:Sure... (Score:2, Funny)
-Microsoft ad campaign
(mods: don't hurt me. I mean nothing but to contribute to good discussion.)
He's got a point (Score:5, Insightful)
On the other hand, high performance usually comes through special hardware. And on that hardware, I think Linux could be the right thing (modulo some patches).
Re:He's got a point (Score:2)
Flame Bait? (Score:3, Funny)
Now, if the CTO of Cray Canada started talking about your mother than I think you're morally entitled and required to respond.
In other words, another PR opportunity (Score:2, Redundant)
Cray used to be a big name in computing but unfortunately for them, they are a relic now. They had their day and it hard to believe that they will be able to compete effectively against Beowulf clusters and Linux mainframes that IBM is pushing. With IBM's public love and
First... (Score:2)
I guess all those universities using Linux clusters are a figment of our imaginations.
It's not the vendors... (Score:2, Informative)
Methinks Cray is feeling a little threatened...
Maybe so (Score:3, Insightful)
Maybe so but not everyone can pull a Cray out of his ass when they need horsepower. A Linux cluster is affordable, a Cray is the thing of wet dreams..
If it walks like a duck, and talks like a duck.... (Score:2, Interesting)
I guess they're not happy about being only #19 on the Top 500 Supercomputer List [top500.org]. Linux is considered faster than they are according to the list.
The 'ol ad-hominem attack of "if you can't beat them ligitimately, attack them personally" just doesn't cut it Paul. Build a be
Re:If it walks like a duck, and talks like a duck. (Score:5, Informative)
A cray processor has eight floating-point units running at 800Mhz. The big Mac cluster (for example) uses G5 processors which have 2 FPUs at 2000Mhz. Thus the cray has a ~40% advantage. However, the G5 processor has ~4GB/s memory bandwidth. The Cray has ~50GB/s memory bandwidth. If you have a problem that needs to do a HUGE amount of math on a tiny amount of data, the G5 will rock. If you have a problem that needs to do a HUGE amount math on a GINORMOUS amount of data, buy the cray. (for a GINORMOUS amount of money too)
Similaraly infiniband (ala the big mac) is really hot in the cluster interconnect space because it gives 2.5GB/s per node. The Cray gives you 51GB/s.
You need to move a little data, buy a cluster. You need to move a lot of data, buy the Cray.
There's no one solution for all problems.
Efficiency and cost argument (Score:4, Interesting)
the list (Score:3, Funny)
Funny... (Score:3, Interesting)
Wish I'd been there so I could have slapped him after about 3 seconds of stunned silence.
The next big thing? (Score:2)
Problem (Score:5, Interesting)
Granted there are many codes (and more every day) that will run on clusters, the big iron will never die.
Just because we love Linux.... (Score:5, Insightful)
There are real issues that differentiate mainframe/supercomputers from large, powerful, clusters.
Of course this all depends on your definition of an HPC. But I believe that it's reasonable to say that if parts of your computer are connected with low bandwidth connections (10/100,gigabit) they just can't handle the same kinds of transactions that a computer with parts that are connected by 10 gigabit or 1000 gigabit connections or whatever it is nowadays.
As far as I know if you're deploying a large database it's still advisable to have a big huge IBM mainframe or a Unisys box or a Sun 10k instead of 4,8 or 16 clustered 8 proc machines.
My point is there are valid arguments for not including clusters of commodity hardware in the HPC category.
In my mind they aren't High Performance Computers... they are High Performance Clusters of Commodity Computers.
~foooo
Linux has failed you (Score:3, Funny)
Partly right, partly wrong.... (Score:5, Insightful)
Other applications require the breakneck interconnect speeds that large Cray / Sun / etc.. build on. When the data being calculated on one CPU requires data from CPU2 to continue its calculations you don't want to have it wait for 100mbit or even 1gbit ethernet speeds. Even quicker interconnects such as SCALI [scali.com] are going to be slowed by PC bus speeds.
Cray fills an important niche for those who can afford it.
Different tools (Score:5, Insightful)
However, dismissing linux cluster technology automatically is dumb. In many cases, it provides more than enough cpu power and I/O bandwith to support your reason for getting a supercomputer, and probably at less cost than the other options.
Its all a matter of determining what you need the computer to do, determining your budget, and get the best system in your budget for the uses you have for it. Sometimes that will be a Cray, sometimes a Linux cluster.
What else d'ya expect him to say? (Score:2, Redundant)
The simplest rebuttal is that its not what you call it that matters but what you can do with it. And, judging by the ubiquitous deployment of linux clusters, the answer seems to be "almost anything under the sun".
Says who? (Score:4, Funny)
Can you multithread your application? (Score:5, Insightful)
What Cray's rightfully pointing out is that for most business applications, however, distributed computing is not a viable option. When processing on a transaction basis, the transactions often need to posted in the exact order they were recieved, which means they must be taken serially. In those situations, the programs can't multithread work out to the other processors so well, and the cluster will end up running at roughly the speed of just one processor while the others waste clock cycles waiting for something to do.
The cluster isn't the solution to everything. Nor is the supercomputer. You've gotta think about the job, then figure out which tool is right for the task.
Re:Can you multithread your application? (Score:3, Informative)
These are not the Droids you're looking for.... (Score:3, Insightful)
His rhetoric is quite predictable, actually. He talks at some length about how and why clusters of PCs can't get the job done, and how clustering is inherently inferior to a REAL SuperComputer, then goes on to describe how their new product (which sounds suprisingly like a cluster of propreitary machines) can work. Repeat the above as it applies to the management software.
If clustering doesn't work, and Supers are better / cheaper, explain why large companies (Pixar, NVidia,
Note that this does NOT mean that clusters are suitable for ALL traditional SuperComputing tasks. It really depends on the problem. If the problem is better solved with a vector processor, then a vector machine (like a Cray) is what you want. If the problem is solvable in parallel, then a cluster might be the right answer.
Cray has some points. (Score:5, Insightful)
In truth, such machine will always have a certain performance advantage over traditional clusters. The question is, will the price point be low enough to invalidate the idea of just adding more boxes to the traditional cluster.
He's wrong, but he's also right. (Score:5, Informative)
Obviously, this guy is plugging the new Cray X1 architecture, which really is quite promising. For instance, check out this paper [sc-conference.org] by some folks at Oak Ridge National Lab that appeared in Supercomputing 2003.
Of course, since this is Slashdot, I expect that there will be a deluge of posts decrying everything about the new Cray machine because it commits the cardinal sin of NOT USING LINUX. Oh, the horror!
Marketing BS, but he has a point (Score:3, Insightful)
Well... he is sort of correct... (Score:5, Interesting)
What really makes a difference between an HPC cluster and your normal every day cluster is the hardware interconnects used. There is a comment in the artical that refers to not using I/O for memory and message passing. I am not quite sure what he means by that, but I am guessing that he is saying that the network is not used for shared memory/message passing (MPI/openMP/SHMEM).
If a cluster can limit the impact of latency between nodes either through smarter software or faster interconnects then I can't see any reason not to concider a linux cluster as HPC.
Clusters without smarter software tend to be a real difficult coding platforms. Some developments with things like globally shared memory might make the difference, but there will still be the problem of latency between nodes.
That's like saying... (Score:3, Insightful)
That's like saying that the automobile is not a high performance team of clydesdales. That's true, but it may be irrelevant. If it can get you there faster or better, I guess it doesn't matter.
Yawn. (Score:3, Insightful)
Strictly He's Correct (Score:3)
but practically, the performanc is "high enough" and certainly a helluva lot cheaper than buying a custom system.
It's just like the old days, except more so:
and you can end up paying a lot of money to squeeze out that extra performance.Given that Linux clusters can achieve speeds in excess of a teraflop, that available dollars for computer purchases are finite, and that per processor performance and price performance is increasing, the market size for the world's highest performing machine is rapidly vanishing to a set of measure zero.
Good points but no cigar (Score:3, Insightful)
Moreover many HPC applications actually scale quite well on clusters of Linux systems. Affordable interconnect infrastructure is increasing in bandwidth and reducing in latency, further broadening the scope of the problems these clusters can tackle. In addition each node can now comfortably have 2 or four processors giving even better bandwidth between CPUs sharing a node. With 64 bit processors and operating systems now available the final barriers to very impressive easy to use HPC Linux clusters have been removed which is exactly why Cray now sees them as a threat. Now is probably the worst time to talk of how a cluster is not a supercomputer. Clusters form a class of supercomputer that can now handle most supercomputer tasks. True there are classes of problems that the dedicated supercomputer systems CRAY sells will excell at, however clusters are useful workhorses in the supercomputer world and hold their own.
Todays supercomputer problems are tomorrows computer problems and Cray must continue to find new classes of problems to solve as they always have, rather than attacking competing technologies, people will use clusters where the clusters meet their needs.
Parallel Programming. (Score:3, Informative)
An example is when I took a course in Parrallel processing we used a MassPar system which had 1024 processors in a grid formation. Now woring on that system I was able to sort a list of a million random numbers way faster then my Duel Processor PC could.
But on the flip side when I ran a program on the MassPar that wasn't designed parallel processing (emacs) it took upwards of 3 minutes to load it due to the age of the computer. While my PC could open up emacs in a split second. So on the clusters even the fastest in the world a Cray that may not be the fastest could actually beat it on many applications because of the faster bus comunication.
Whatever (Score:3, Interesting)
The Cray XD1 looks like a nice system, but there are only theoretical performance values given, and noone can go out and buy one of these things yet. I also don't know how much these guys cost.
I love this statement:
Linux clusters do have a place. "For applications that require low performance, they are a cheaper solution," said Terry.
Yeah, when we spend a million+ dollars on a supercomputer, we are thinking of low performance, because our applications require it. Thanks.
I'm guessing this guy is a wannabe marketer who got stuck in a CTO position. There are plenty of HPC vendors out there, and trust me if this XD1 has a good price/performance and they work (this is key), then people will buy them with little questions asked. Otherwise, this whole article is just an advertisement that makes many statements without any evidence that the XD1 is any better than 4 Xboxes connected together over a serial connection. Next....
doesn't this CTO of cray remind u of someone? (Score:5, Funny)
"There IS no Linux in high-performance clusters."
"There IS no Americans in Iraq."
OMG! It's the former Iraqi mis-Informed-ation minister!
Especially when 2004 has been dubbed the year of the penguin, it's wreckless to claim that Linux can't be used in HPC's.
Hell, just look at the current top500 list [top500.org]. There's no Cray in the top 10 but there are two Linux based clusters there (and one based on OSX [FreeBSB based]).
Here's a few:
NCSA's IA32 Linux cluster [uiuc.edu]
NCSA's IA32 Linux cluster [uiuc.edu]
Space Simulator Clust at Los Alamos [lanl.gov] (SS51G based; makes me proud as I have a SS51G too)
Beowulf - used in many Linux clustering projects [beowulf.org]
Linux clusters at Los Alamos [llnl.gov] (they seem to have more than one)
Virginia Tech's Supercomputer X [vt.edu]
FUD and Thunder-Mongering (Score:3, Interesting)
Although this statement reeks of FUD, he's right about one thing: a cluster is not an HPC... that's why its called a cluster. But to say that a cluster is 'unmanaged' is one hell of a stretch IMO. All in all, he's just arguing semantics: nothing to see here, put down your flamethrowers, move along folks.
Since this is slashdot, I'll add that the rest of the article is full of choice quotes all of which point squarely at basic FUD + marketing spin for their new cluster-cost-like product.
It seems to me that Cray is just plain bitter that Linux (through all the cluster solution providers) has managed to steal Cray's thunder at a mere fraction of the cost. Cray's probably even more bitter that folks are willing to sacrifice performance (at least from Cray's perspective) just to save a buck.
Okay, this is Cray we're talking about here: people are saving millions of bucks all over the place by using clusters instead of big expensive machines.
And guess who wants 'their' slice of the pie back.
Vector based computing (Score:3, Insightful)
You guys are giving cray too much credit (Score:3, Informative)
That's great and all, but for a single threaded application a cray isn't even going to smash your modern top of the line home pc by too terribly much.
crays are massive smp systems, they need a multi-threaded app to take advantage just as much as a cluster does. The difference is in the bus speed. A cray has a much faster bus, and with equivelent processing and memory it will excel with a number of small quickly terminated threads, whereas a cluster will as well or better with larger more processor consuming threads.
Why would a cluster ever do better? Simple, although a cluster has a drastically slower bus, there is memory local to the processor in question so there is much less congestion on the bus, and since if your shelling out for a cluster you will be switching rather than hub style whatever you do there will be almost without collisions and bus contention. Each node has it's own ram so there isn't much of an issue with contention for the bus and much greater memory throughput.
So like I said, it's all about how fast threads spawn and terminate, because if your rapid firing threads then you will doing alot of communicating between nodes over the slow bus (network), if your sending good sized chunks of data do something and keeping your nodes busy they will spend more time working and less time communicating results and your cluster will tromp all over that cray.
They're all clusters now anyway (Score:3, Insightful)
Every other machine in the top 10 is built from standard processors. The old DEC Alpha, PowerPCs, and IA-32 predominate, with a few Itanium machines.
Because supercomputers today have several thousand processors, they can't even be big shared-memory multiprocessors. Speed of light lag in the interconnects would slow everything down. It just takes too long for the signals to make it across the room.
So all supercomputers today are clusters of one kind or another, fast machines with slower interconnects between them. The hardware architecture revolves around interconnect schemes. The software architecture revolves around working around the limitations of the interconnect schemes. Tightly coupled problems don't map well to such machines.
Bear in mind that we're talking about clusters of uniform machines located near each other with gigabit or better interconnects. We're not talking about "clusters" consisting of spare-time programs out at the end of Internet connections. Those are useful only for problems with almost no coupling between parts. Such problems are usually low hit rate search problems, like cryptanalysis, SETI@HOME, and such.
Yes, there's the Cray X1, the last of the liquid-cooled monsters, but it looks like the only customers who bought one were Government agencies with old Cray machines.
Wrong Source (Score:3, Insightful)
A cluster isn't a supercomputer, by definition, but for many jobs can be equal or better. In other words: Those 2 oxen cost more, consume more resources, are only useful for the one job (pulling a plow) and only benefit a single owner. Those 1024 chickens cost less, consume less resource, are useful for many jobs besides the one (including laying eggs) and benefit their many owners.
Re:Checking with the TOP 500 Supercomputers I find (Score:2)
The Cray will scale up (Score:5, Informative)
Re:Checking with the TOP 500 Supercomputers I find (Score:3, Informative)
Re:for the love of... (Score:2)
Having seen a small cluster in operation, the Cray officer does have some good points. It still boils down to whether their improvements are worth the extra cost.
Re:SGI (Score:2, Insightful)
SSI is where all CPUs can see all memory as if it was local. They are also Non-uniform memory access which means all the memory it sees is not as fast as all other memory, but really ALL single systems are like this. For example each CPU can address the entire TB of memory that is in the system, but reading from one m
Re:Well.. (Score:5, Insightful)
Oh, here's the TOP500 list [top500.org], btw.