Factual 'Big Mac' Results 566
danigiri writes "Finally Varadarajan has put some hard facts on the speed of the VT 'Big Mac' G5 cluster. Undoubtedly after some weeks of tuning and optimization, the home-brewn supercluster is happily rolling around at 9.555 TFlops in LINPACK.
The revelations were made by the parallel computing voodoo master himself at the O'Reilly Mac OS X conference. It seems they are expecting and additional 10% speed boost after some more tweaking. Srinidhi received standing ovations from the audience.
Wired news is also running a cool news piece on it. Lots of juicy technical and cost details not revealed before. Myth dispelling redux: yes, VT paid full price, yes, it's running Mac OS X Jaguar (soon Panther), yes, errors in RAM are accounted for, Varadarajan was not an Apple fanboy in the least... read the articles for more booze."
Heer is and arictaclael on it (Score:0, Informative)
Re:Dumb Question... (Score:5, Informative)
It's highly dependent on the interconnects, the topology of the network, the software that does the clustering (i.e., that actually makes the nodes available for parallelized word), etc.
So minor tweaks can have major effects, and getting it tweaked properly is quite an accomplishment.
Re:Full Price? WHY?!? (Score:5, Informative)
Re:Full Price? WHY?!? (Score:4, Informative)
Re:Full Price? WHY?!? (Score:2, Informative)
A Little Perspective Here (Score:5, Informative)
Here's a quick rundown:
Dell - too expensive [one of the reasons for the project being so "hush hush" was that dell was exploring pricing options during bidding]
Sun (sparc) - required too many processors, also too expensive
IBM/AMD (opteron) - required twice the number of processors and was twice the price in the desired configuration; had no chassis available
HP (itanium) - same
Apple (IBM PPC970) - system available with chassis for lowest price
Re:Simply amazing (Score:1, Informative)
Just a thought on "home-brewed" means (Score:4, Informative)
Ignoring the "brewn" part of things, since when does "home-brewed" mean "designed and funded by a major university"?
I usually think of "home brewed" as something that someone put together at home. With their own money. In their spare time.
This is *not* a home-brew supercomputer, it is an institute designed and created super computer.
That is all.
Re:Why didn't they use Darwin or Gentoo? (Score:3, Informative)
Second, the difference caused by increased optimization in the kernel, for an application like this, is relatively insignificant, simply because most of the work is done in user-space. In fact, any decent super-computing application will do its best to minimize system calls (allocating memory pools, chunking I/O, etc). About the only place the kernel is really involved is in sending/receiving data, and my bet is that optimization here would make relatively little difference, in light of the delays introduced by the network itself, interfacing with the card, etc, etc.
Third, I highly doubt they're running any other software on the cluster nodes that would impact performance. Again, if they were doing that, they'd benefit more from hiring a new system architect.
So, basically, what I'm saying is, comparing your little KDE desktop to a supercomputing application is laughable at best.
More info on the G5 Cluster (Score:5, Informative)
Here is da slide-show [vt.edu]
Supercomputer article (Score:5, Informative)
For anyone interesting in learning a bit more about what some of the issues are when creating a super-computer, you might want to have a look at the following:
Red Storm PDF [lanl.gov]
The article is talking about Cray/Sandia's new Red Storm machine, a supercomputer using over 10,000 AMD Opteron processors that is expected to be competitive with the Earth Simulator for the #1 spot on the Top500 list. It does, however, talk about a lot more than just the specifics of this cluster, describing what some of the bottlenecks in supercomputers are and how to avoid/work around them.
Re:Memory errors? (Score:2, Informative)
Anyone seen any actual TECHNICAL details on this point, ie not just some Mac fan yelling "Deja Vu, DEJA VU!!!"?
The slashdot quote is grossly misleading. At the O'Reilley conference they were very clear the machine does NOT CORRECT MEMORY ERRORS, but they would like to use ECC in the future. The current tools are just intended for restarting failed/crashed jobs, not to detect silent memory errors.
Is it just me (Score:1, Informative)
Re:Executive Summary (Score:3, Informative)
Maybe you didn't read close enough, because the articles specifically state that he didn't compare only to Intel and that he found the Opterons to be too expensive. I'm just saying, because I think a lot of people did see a quote in the article mentioning Opterons, and you seem to have missed it. Thought you'd like to know.
And if you decide to disbelieve whatever you don't find convenient in a new story, you should rethink your statement about keeping religion and technical discussion separate, because you're really not.
No offense, but I think it should be pointed out that not only Mac fans are zealous.
Comment removed (Score:5, Informative)
The REAL power usage numbers (Score:5, Informative)
Ugh, this is getting old.
Red Storm, the machine by itself itself, uses 2.0MW.
Big Mac and all of its networking gear uses less than 0.75MW. The supercomputing center itself (building, air conditioning, UPS battery charging equipment, and the 1100 G5s) is fed by a 1.5MW substation feed. They're still not even maxing out the substation.
The latest, fastest Opterons (not the scaled down low-power Opteron for blade servers) consume 53 watts at full clock. PowerPC 970 @ 2 GHz consumes 48 watts. The U2 and K3 motherboard chipset on the dual G5s uses just as much power as the PowerPC 970 "G5" processors. Hell, the power supply in a dual processor G5 system is 550 watts. 550 x 1100 machines = 0.61MW.
Re:Power PC 970 and G5 (Score:3, Informative)
Re:Favorite Quote - Correction About Apple (Score:5, Informative)
I usually never reply to these things, but I think it is funny that people are arguing about how he ordered on the Apple Store. I find it even funnier that people would even go to the Apple Store and try. It was a joke! There were a lot of dedicated people at Apple, including myself, that helped to make this dream become a reality. The "myth" that I would like to clear up is that Apple DID have a clue and a lot of great people at Apple have been working really hard for that last few months, making a lot of personal sacrifices to make sure that all the awesome work from Dr. Varadarajan and the rest of the cluster team could be possible and successful. That's my 2 cents.
Jerome Holman
Apple Campus Representative @ VT
http://filebox.vt.edu/users/jeholman [vt.edu]
Re:When They Switch It to Linux (Score:2, Informative)
Re:a lot of people get the math wrong! (Score:2, Informative)
2 FPUs/ CPU * _2_ floating point operation per cycle per FPU = _4_ flop per CPU per cycle
_4_ flop per CPU per cycle * 2 Gcycles per second = _8_ Gflops per CPU
_8_ Gflop/s per CPU * 2 CPU per machine = _16_ Gflop/s per machine
Re:a lot of people get the math wrong! (Score:2, Informative)
A fused multiply-add is f0 = f1 * f2 + f3, which is two floating point operations in a single instruction. Each FPU on a G5 can execute an FMADD each cycle. So:
1 FMADD per cycle = 2 flop/cycle * 2 FPUs = 4 flop/cycle * 2 CPUs = 8 flop/cycle * 2 GHz = 16 Gflop/s
Re:Too bad some software patents will be filed (Score:3, Informative)
Besides the prior art issue that others mentioned, academic research is not subject to patents. So university researchers never have to pay to license patents.
Re:if they paid full price, it's not a great deal (Score:3, Informative)
Re:Full Price? WHY?!? (Score:1, Informative)
Apple has multiple online stores. One of which is for educational institutions. Another is for business. Another is for government.
Unlike the end-user store (maybe even the student store) which you are familiar with (and I am giving you the benefit of doubt that you actually researched this), the other stores get two things:
1) An account-based discount, which varies from account to account. Some companies get 2% off, others get 15% off, yada yada yada.
2) A volume-based discount, based on the quantity of systems in the order being placed.
For large orders it's also pretty commonplace to get free shipping on top of that.
Full price means "no special pricing", which means Apple didn't wrangle up some magic numbers just for VT. They paidthe same price as another university would've paid if they bought 1,100 G5s (assuming this fictional univeristy purchased the same $$$ last year from Apple as VT did, which is how the account-based discount works).
Go find another little drum to beat. May I suggest the one between your legs?