Cell-based "Roadrunner" Tops Elusive Petaflop Mark

prunedude writes "The NY times is reporting that an American military supercomputer, assembled from components originally designed for video game machines, is more than twice as fast as the previous fastest supercomputer, the I.B.M. BlueGene/L. To put the performance of the machine in perspective, Thomas P. D'Agostino, the administrator of the National Nuclear Security Administration, said that if all six billion people on earth used hand calculators and performed calculations 24 hours a day and seven days a week, it would take them 46 years to do what the Roadrunner can in one day."

Comments

Re:Question

[avalys]

It will be used for nuclear weapons simulations - primarily for investigating issues related to how warheads will perform as they age.

Re:Question

[Anthony Rosequist]

Before it does weapons simulations, it will first work on some scientific problems, like model testing to predict climate change.

After it's done with that (I wonder how they will determine what done is...), it will go classified and do nuke simulations.

Change in paradigm

[karvind]

If one looks at http://www.top500.org/ list and compare the CPU frequencies of the top supercomputers - all BlueGene CPUs were running at less than a GHz. And it seemed those low power cores were key to HPC (high performance computing). Cell and opteron - both run at multiple GHz and (presumably consume more power). IBM still has next generation of BlueGene/Q in works and is also for +Petaflop computation.

Re:exaflop, zettaflop, the yottaflop and the xeraf

[DogDude]

Military taking the lead on computing as usual. Why is the military so much more progressive (with practical results) than any other institution of government?

Are you kidding?

Re:The future

[Thalin]

This is actually based on Cell 2 or as IBM marketing likes to say it "Cell eXtreme"!

Cell 1 (the Playstation chip) didn't have the double precision floating performance to achieve the petaflop mark; Cell 2 is far better on that front.

Re:Not in perspective - this is a media number

[jareds]

How fast it could break the 128 bit encryption used when you log onto your bank's web page to pay your bills (this might also be understandable and would probably be a bit scary)

No, not at all scary. It's apparently twice is fast as the BlueGene/L, which apparently set a record of 478.2 teraFLOPS. Let's assume it takes 1 floating-point operation to test a single key, which is a gross underestimate. We'll thus assume the Roadrunner can test 10^15 keys per second. Testing 2^128 keys would then take about 10^16 years.

This CELL is not single precision

[raftpeople]

The CELL processor is single precision, which translates into wrong answers most of the time. Me guess is that for problems requireing double-precision numerics, you should divide CELL based supercomputer by 10 to 100 (software emulation of double precision is MASSIVELY SLOW), so this is really a teraflop machine. No big whoop...NEXT!!!

Things move fast in technology Jethro, including this 2nd gen of the CELL proc, this is what you missed:

Double Precision FP - 190TFLOPS (5 times faster than 1st CELL)
Memory: Expanded to 32gb
Memory: DDR2 instead of Rambus
65nm (I know, I know, but it's better than 90nm)

Re:Cell processor

[BiggerIsBetter]

One thing to remember is that there is various iterations of the cell processor. The Xbox is a 3 core version The Playstation. I believe the Playstation is a 6 core processor. The roadrunner will use a 8 core processor. IBM originally discussed having a 16 core processor. There was not much talk about it afterwards. My guess is that there was significant bus contention issues. The original Power4's shut down one of their cores while running at full speed to avoid contention. The Power6 was designed to overcome these issues. No, the XBox 360 has a three core PowerPC processor, not a Cell BE processor. The Cell BE in the PS3 has 1 PPE (Power core) and 7 SPEs (that "other" CPU core), while IBM apparently gets to use the fully functional Cells (PPE + 8 SPE) in their more expensive hardware. Those Cells with even fewer functioning SPEs might end up in HDTV TVs or similar.

Re:Summary should have a shout out

[chrysrobyn]

From what I've heard (I'm no expert), these processors are good at certain types of calculations, but horrible at others. Ask a Cell to run Folding@Home, and it'll be blazing. Ask it to do general-purpose computing, though, and you'll quickly see the strength of other processors.

You're precisely correct. Cell's strength is in very predictable workloads (ones it can perform without branch mispredict penalties), very parallelizable workloads (ones that can be distributed over 6-8 SPU's / SPC's) that fit within 256 KB of local storage per SPU (manually managed cache, mapped to main memory). The non-double precision floating point enhanced version's (the version in the PS3) strength is further limited to integer and single precision floating point workloads. Roadrunner's Cell-DP eliminates that last limitation. While video games, encryption, nuke simulations and anything else that involves matrix manipulation can really stretch their legs on such a beast, general purpose computing won't find a benefit.