Berkeley (CA) – Researchers from the Computer Science Division at UC Berkeley and Lawrence Berkeley National Laboratories (CRD/NERSC) recently submitted a paper to the IEEE, highlighting the subject of scaling an optimized Lattice Boltzmann Simulation on popular supercomputer architectures. Intel may not be completely happy with the findings: At least in this very specific environment, the Xeon and Itanium 2 processors did not scale very well, while Sony’s Cell BE came out on top.  

The paper itself was published as “Lattice Boltzmann Simulation Optimization on Leading Multicore Platforms” and tries to shed some light on a specific area of socket-per-socket HPC (High-Performance-Computing) scaling in supercomputer environments. As reported first by HPC Wire, the scientists evaluated AMD’s Opteron (Santa Rosa), Intel’s Itanium 2 and Xeon (Clovertown), as well as the Sony-Toshiba-IBM Cell BE and Sun’s Niagara 2 processors. The researchers apparently spent quite some time on optimizing the application itself, rather than the hardware. This optimization was claimed to have resulted in a 14x improvement over the original LBMHD code (Lattice Boltzmann magneto-hydrodynamics).

 

 

According to the paper, the best scaling was delivered by the STI Cell BE system, followed by Sun’s Niagara 2, AMD’s Opteron, Intel’s Xeon and Itanium 2.

We contacted Intel to discuss UC Berkeley’s findings, but Intel declined to comment as the company said it wasn’t familiar with the content in the paper.

However, Lattice Boltzmann applications are known to have a high demand for system memory bandwidth and this fact may have put Intel’s system at a disadvantage in this specific test: Intel uses FB-DIMM 667, AMD DDR2-667, Niagara 2 FB-DIMM 667 and Cell the ultra-fast (and Rambus-based) XDR technology. Until Nehalem (Bloomfield core) and its integrated triple DDR3 memory controller comes along, Intel is likely to trail the pack in such tests. Regardless of the name of your Xeon processor, whether it is Cloverfield, Harpertown or Tigerton, any bandwidth-intensive application will cause a poor scaling performance on a FSB-burdened platform. In this UC Berkeley test, Intel’s Xeon and Itanium 2 followed the pack with a substantial distance.

It is interesting to note that even AMD’s Opteron processors were scaling almost in a linear fashion when additional CPUs were added. The Xeons scaled only by 43% on a socket-per-socket basis.

The lesson learned? Obviously, there are different benchmarks out there, most of them stressing a particular discipline. This specific test indicates that you should not run a memory bandwidth-intensive application through a Xeon or Itanium 2 system, if you have the luxury of having an Opteron, Niagara 2 or Cell system available as well. But does it mean that Xeons and Itanium generally scale worse than other architectures? No. There is more to supercomputers than memory bandwidth and Intel certainly has the edge on pure processing horsepower at this time.    

 

old news

Apr 29, 2008 12:20     

Everyone knows intel chips don't currently scale well over a 4p environment. The whole nahelem and quickpath business is supposed to fix that.
Pete report abuse vote down vote up Votes: +6

XDR

Apr 29, 2008 12:24     

Theo - Do you have any inclination as to when we might see XDR in our desktops? I've loved Rambus since the P4 days and I want the best memory that's available now.
robert report abuse vote down vote up Votes: +3

If Rambus is less greedy

Apr 29, 2008 14:29     

then we would have had their memory everywhere.
nofubu report abuse vote down vote up Votes: -5

horsepower Niagara 2 < Intel ?

Apr 29, 2008 14:43     

"Intel certainly has the edge on pure processing horsepower at this time" IMHO, you should review your statement. Sparc cpus are know for their horsepower at low frequency. Plus it is foolish to compare a Niagara 2 with an Intel cpus. They target two different platforms/customers. It's like comparing the engines of a Prius and a BMW M3.
olivier refalo report abuse vote down vote up Votes: +1

XDR

Apr 29, 2008 19:00     

Toshiba Notebooks that include the Cell technology and XDR memory were announced at CES 2008 and Toshiba expects to have them in the marketplace this summer.
Lenny report abuse vote down vote up Votes: +1

RE: Niagara vs. Intel...

Apr 29, 2008 20:42     

Actually... both Niagara 2 and Xeon are on the same race-track. You can say that they're Toyota hybrid and a performance BMW, but they still race the same race, for same millions and millions of dollars worth contracts.
Theo Valich report abuse vote down vote up Votes: +2

Theo apologizing for Intel again. What's in the swa...

Apr 30, 2008 01:20     

Theo apologizing for Intel again. What's in the swag bag this time?
Simon report abuse vote down vote up Votes: -2

RE: horsepower Niagara 2 < Intel

May 01, 2008 10:02     

Sun's UltraSparc's sure packs a punch, but as far as your statements "...foolish to compare a Niagara 2 with an Intel cpus": Niagara and Itanium DO compare (Not Xeon) and there the Intel Itanium ROCKS (Before AMD flunkies flames me, EVEN IF IT DID NOT TAKE OVER LIKE INTEL HOPED, IT IS STILL THE BEST uARCH)
Nixo report abuse vote down vote up Votes: +0