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New Apple Super Computer (Army)

can we please keep this computer-focused?

We all have an opinion, good or bad, of the US Army, but the point is that this is great for apple. First, because it's a 5.8 million dollar order. But second, because people are apparently starting to realize the power-per-dollar that you get with an x-serve cluster. Hopefully, this will just be the second of many such clusters.

(p.s. how about they get VT's Big Mac back on line???)
 
Three words

> global thermonuclear war||

Do you think they could add a 300 baud modem to one of them for me, for unspecified reasons? :D
 
OS X in the top 5

Come November, I wonder how many Top 5 supercomputers will be running Mac OS X. I don't see a date for MACH 5, but Big Mac should be back long before then. 2 of the top 5 seems likely then--maybe more!

And why do I get the feeling that the waiting list for Xserves is going to remain in the realm of iPod Minis?
 
alexf said:
Yes, well, unfortunately this is an inherently political matter.

However, I will save my comments for a political forum.
Click to expand...

Politics or policy of the New American Century aside - it's not the army who's directly purchased these - i.e., the Secretary of the Army has not all of a sudden gone Mac happy. It's a military contractor that won the work set out in an solicitation or has been approved for on-going work, and was in turn able to purchase a system with some amount of their contract award. Think of it like this - you wouldn't call Boeing or Lockheed Martin the Airforce, would you? Same sort of deal.
 
For reference the submarine order was for the sonar systems on US submarines.

deepkid said:
Would seem like flight simulations would need speedy networking also. I guess we'll see once they get it up running. BTW, I did read that statement about networking needs in the article, but it still left me wondering.
Click to expand...
CFD packages are very computationally limited and lead themselves to clustering very well. It won't do as well on the Top500 list but the army isn't buying the computer just for that.
 
cool, apple. but what it seems to me is that apple is becoming a inexpensive provider of computing power, which seems to be just a larger scale of that niche market thing. not all businesses need supercomputers. when apple computers start being used to do mere daily office work, that's where the growth will come from. but the larger the company the more expensive and difficult it is to make that switch. i could see a small startup company that begins with macs and grows with macs as being the most probable situation. i am personally happy with apple's performance. they make an awesome personal home computer and are always finding ways to innovate. i would be happy with just that, but i guess we'll see how things go.

heh, fine no politics. :rolleyes:
 
I don't get it -- what's the point of having one of the fastest computers? Bragging rights? What do they do on these computers, Photoshop tests?

// narco
 
narco said:
I don't get it -- what's the point of having one of the fastest computers? Bragging rights? What do they do on these computers, Photoshop tests?

// narco
Click to expand...

in this case probably stuff that were not allowed to know about ;)
 
First to note, that Virginia tech is not on the list because they do not have a supercomputer running so they had to drop out.
With the rumored 2.3 Ghz G5 Xserve update couldn't we see alot more speed out of them. Apple doesn't tell us the speed and I think everyone is presuming 15 Teraflops is with the 2.0 Ghz dual G5 Xserve. How do you calculate the speed of a super computer made up by 1500+ running dual 2.3 Ghz G5. With the itanuim supercomputer running at 20 tf, and we reach 25 tf hello 2nd.
 
Latency matters

deepkid said:
I wonder if they'll run into any bottlenecks using gigabit ethernet instead of InfiniBand. Would that affect them truly reaching 15 teraflops...
Click to expand...


Interconnect latency matters a lot. The "teraflop" benchmark is dependent on some very creative definitions with a very long list of conditionals. Only a very small number of possible applications will see anything remotely close to that performance with Infiniband, and even fewer with GigE. The codes they will be running are reasonably well suited for the PPC architecture though.

Differences in interconnect latency determine how an application will scale across a cluster. Some applications are more dependent than others, and identical machines with different interconnects can show a huge difference in performance even if the interconnects have roughly the same bandwidth. Clusters with very low latency interconnects are capable of running far more applications reasonably well than clusters with high latency interconnects. The Top500 benchmark is not terribly dependent on interconnect performance, even though most supercomputing applications are.
 
mactarkus said:
... I remember there was a big purchase by the US Navy a year or so back to outfit a submarine. I wonder how that project is progressing.
Click to expand...

IIRC the the Navy bought G4 XServes that ran Yellow Dog Linux, I forgot the name of the company that sold Apple hardware running YDL, if you go to the site I'm sure you will find info on it
 
Sunrunner said:
I wonder why that would be ... isn't network bandwidth one of the primary factors that kill the speed of cllustered computers?
Click to expand...


It is usually the interconnect latency rather than the bandwidth that kills clustered computers. Cluster interconnects like Myrinet and Infiniband don't have any more bandwidth than various flavors of Ethernet. What you are paying for is an order of magnitude reduction in latency versus Ethernet. That is what makes it worth the price, not the bandwidth.

And the folks that buy huge ccNUMA systems get an additional order of magnitude reduction in latency. Each step up in latency reduction costs a significant premium.
 
quagmire said:
First to note, that Virginia tech is not on the list because they do not have a supercomputer running so they had to drop out.
With the rumored 2.3 Ghz G5 Xserve update couldn't we see alot more speed out of them. Apple doesn't tell us the speed and I think everyone is presuming 15 Teraflops is with the 2.0 Ghz dual G5 Xserve. How do you calculate the speed of a super computer made up by 1500+ running dual 2.3 Ghz G5. With the itanuim supercomputer running at 20 tf, and we reach 25 tf hello 2nd.
Click to expand...

The theoretical performance of a PPC970 is

2 Floating point units X 2 flops per clock cycle x the GHZ of the CPU

Therefore 1566 x 2 cpus ea X 8 GigaFlops = 25.06 TF Theoretical

SO I would assume they are using the 2.0s

Now they claim they will get about 15 TF actual

15/25= .60

So they are assuming that they can reach about 60% efficientcy on Linpack

That is fairly high percentage considering the use of Gigabit Ethernet, but it could be attainable with some good performance tuning.....

1st it would depend on how much memory the nodes have.... the more the better.... because a larger LINPACK problem can be run which will cause the system to spend more time calculating than sending messages...

2nd. The compiler version makes a huge difference......If it was my cluster I would use IBM's xlf compiler.

3rd. The BLAS libraries you use are very important.... I saw the other day that GOTO has just finished a set of customed tuned BLAS libraries for the PPC.... If it was my system I would use them cause GOTO writes the best.

4th. Even though they selected Gig E ..... all Gig E isnt created equal.....
Some are much better than others.... and suprisingly some have fairly low latency......Example Extreme's Blackdiamond is even as low as 10 microseconds....
Now they didnt say whose Gig E they used.... But if they went with Extreme that could help.

5th The MPI you use maters a good bit too..... 3 real choices here....
MPICH.... free
LAM..... free
MPI PRO.... expensive

While mpipro is the best overall
LAM is very quick on TCP/IP
Mpich is more like the middle of the road and kind of the standard in research systems.

6th and Final.... Linpack has a lot of tuning parameters.... If these guys are really good they can squeak some extra FLOPS out of tunning linpack.

So who knows.... maybe they will get 15 TFlops.... heck maybe they will get more.. maybe less....
but at least its another MACINTOSH and a win for APPLE!!!!
 
I remember when...

mactarkus said:
As someone who works for the Department of Defense, this purchase of Apple computers is monumental toward more widespread adoption of the platform. You see, the US Government = Microsoft. Even Linux is still a hard sell most of the time. I remember there was a big purchase by the US Navy a year or so back to outfit a submarine. I wonder how that project is progressing.
Click to expand...

Back in the late 80's/early 90's there was the Government's DeskTop-III (I think it was DT-III) contract, and it was SCO UNIX on X86 (Unisys, IIRC). I remember it because I used to work for an integrated sofware company (Enable) that actually did a port of their popular-with-the-feds DOS software to SCO/X Windows. So, there was a time when the Gov't did something other than MS. Perhaps we will see more and more coolness in the hands of our public servants....

Just imagine the IRS on Macs. Refunds sent out the next day! :eek:
 
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