G4 vs Pentium IV
 

I read with interest the earlier posting comparing the Athlon 1.33 MHz with the 1.5 MHz Pentium IV. However, where does Apple's 733MHz G4 processor rate? Apple claims it can do over 5500 MFLOPs. Does anyone have any experience comparing these platforms?

Re: G4 vs Pentium IV
 

(1). It would be interesting to know whether there are people using Apple computer in CFD analysis.

Re: G4 vs Pentium IV
 

I have an article from people working at NASA who made some experiments with the G4, pentium III, alpha workstations and a CRAY. With an appropriate compiler which can make use of the AltiVEC capabilities (parallel processing of the true RISC powerPC processor), the G4 delivered the least expensive cost per megaflop. Nevertheless, if the compiler cannot make usr of the AltiVec capabilities, the G4 are not meant for CFD...

If you are interested in the article, let me know, I will mail it to you.

P.S. The 5500 MFLOP claimed by Apple are purely theoritical. If you take the LINPACK1000 bechmark on a 1000GZ Athlon or 733PIII it will be aroung 80Mflops.

Re: G4 vs Pentium IV
 

I realize that you can't directly compare the speeds to the G4, but here are some articles which may help:

http://www.barefeats.com/pentium.html (comparison of G4 on photoshop and games)

http://www.arstechnica.com/cpu/1q00/.../g4vsk7-1.html (technical comparison of G4 to AMD)

These aren't true CFD comparisons, but they show that G4, AMD, and Intel are roughly the same speeds. Each processor shines in a different area. Thus the main consideration should be price.

Best G4: $3200 for dual 533 MHz or $3700 for 733 MHz both computers are with 1 GB memory, 40 GB hard drive, no monitor, and a terrible video card. Note: These cannot use more than 1.5 GB of memory (no large simulations possible). Apple doesn't sell good workstation video cards, would a G4 work with one?

Intel: Right now a P4 1.7 GHz with the same options as the G4 above costs about $2700. Note: 4GB of memory can be obtained with the non-apple computers.

Best Intel: On June 4th, 2001 one can buy a dual processor P4 Xeon computer at 1.7 GHz. So far, the prices look to be around $3500 with the same components listed above. Current benchmarks show this is 30-70% faster than a comparable single processor P4...

Best AMD: Soon to be released will be the dual processor AMD computers. These should shave off about $600 from the price of the dual P4 Xeon. The performance is similar to the P4 Xeon but depends on your exact usage.

My conclusion, the price/performance ratio looks bad for the G4 after the dual P4 Xeon is released in two weeks, or when the dual AMD is released.

Re: G4 vs Pentium IV
 

To those who care, I've answered my own question with more research. The G4 can dole out gigaflops as advertised, if the code is specially-tailored to its Altivec Velocity Engine processor. This can be done on platforms such as Code Warrior. The catch is (and there's always a catch), that you get the most dramatic accelerations in speed if you deal in integers. You can still top the gigaflop mark for single precision floating point numbers IF your matrix to be solved is small enough (i.e., can fit in some L-something cache or something like that). When the size of the matrix increases, the actual performance drops accordingly. In the end, this can still be higher that what is currently offered by the 1.5 MHz Pentium 4. However, if you tried to carry out the program with double precision floating point numbers, the Velocity Engine can not be utilized, and the processor speed behaves like, well, a 500 MHz processor.