Last summer, after benchmarking, the Center EP/GF installed the IBM Regatta with 32 CPUs and 32 GByte memory and a peak performance of 166 GigaFlop/s (billion of floating point operations per second). It uses the Power4 microprocessor, a chip with two CPUs clocked at 1.3 GHz. The chip is in itself a multiprocessor system, which is very fast and ideally suited for technical and scientific applications.

The Center, responsible for the airflow, still uses an IBM SP2 computer with 16 nodes, each equipped with one older Power2 processor. Additionally, there is another IBM SP2 computer with 64 Power3 CPUS, distributed on 16 nodes with 4 CPUs each. All the machines are only used by this Center.

All the machines are used in passenger car development for simulations in fluid mechanics, aerodynamics. The supercomputer enables DaimlerChrysler to obtain new results in product development faster and more economically, in particular in the field of engine compartment cooling, thermic security of the car, and thermic comfort of passengers.

Main problems, which are simulated using the Regatta are for example:

• cooling of the car (flow in the engine compartment, cooling)
• flow through the wheel house (cooling of the breaks)
• flow in the interior of the car including the thermic conviniences for the passengers
• thermal simulation of the complete car, simulation of all temperature-critical components in the car.

DaimlerChrysler uses the commercial Programme package STAR-CD of the independent software vendor CD-adapco (in former times they were namend Computational Dynamics). It simulates flow processes and is available on the IBM with the oprating system AIX 5L. STAR-CD is technologically leading in the analysis of flow in the automotive and aerospace industry, in turbo machinery and chemical processes. CD-adapco parallelised the programme very efficiently.

Up to now DaimlerChrysler used its two Unix systems RS/6000 SP very successful and made good experiences with it. With the installation of the new p690 server the compute power grows massively. In benchmarks the 64 Power3 processor IBM SP gained about 60% of the performance of the 32 Power4 processor Regatta. The center checked in the procurement process the computers of other vendors too, the Regatta lay ahead in this specific application. Another aspect has been considered, the footprint. Even in this case the computer offered the highest performance per square meter.

The Regatta is not used as a throughput machine but for long running jobs, one to four days elapsed time. Usually two jobs are processed in parallel, which use 16 processors. Only in specific cases, when fast response times are required, one job runs on all the 32 processors.

The new computer delivers the results faster. On the other hand, the developing engineers refine the compute grid and gain more detailed results than in the past.

The supercomputer delivers DaimlerChrysler much faster and more cost efficient new results, which can be transformed directly in the development of a complex product like a car. Especially in the competitive situation in the automobile market it is extremely important to shorten the development process.

"The Regatta supercomputer helps us to measure up to the risen requirements which the refinement of the computing networks entails. Additionally, turnaround-time of the individual computing jobs could be reduced", stressed Walter Bauer of DaimlerChrysler.