An engineer at NASA Langley has benchmarked
the new Apple G5 workstation for use in computationally expensive CFD analysis.
The jet noise prediction tool, Jet3D, was run on
a dual processor G5 in order to determine performance compared to the older Apple G4 and an Intel Pentium 4 system.
The Jet3D code is written in FORTRAN and C and has been written in both a double precision scalar and vector version. The vector version was optimized to run on the AltiVec instruction set on the G4 and G5 processors and will not run on the Pentium 4 machine.
It should be noted that the G4 and G5 systems had two processors while the P4 system had a single processor. Therefore, only single processor results are presented for the G4 and G5.
Furthermore, it is also important to remember that the G5 is a 64bit architecture whereas the P4 is 32bit. This will have a significant impact on the performance of a double precision code such as Jet3D which is using 64bit words. Lastly, the G5 is at a disadvantage because optimized compilers for the new architecture are not yet available.
Results from running the scalar version of Jet3D show that the 2.0GHz G5 is equal in performance to the 2.66GHz P4 system at 255 MFLOPS (million floating point operations per second).
Results from running the vector version of Jet3D show that the
G5 can produce an impressive 2755 MFLOPS performance on vector optimized code.
From these results, it would seem that the new offering from Apple can hold its own in computational intensive applications such as CFD.