Hi, I Last week I installed the RC5-64 crack distributed.net client on some of my servers, and looked at the various Keys/sec rates of several CPUs. (Notice that the app has cores written in assemby which take advantage of special fetaures of the CPU, like MMX, SIMD , Altivec etc) I had the chance to play with a new (500-550 Mhz I believe) G4 Mac. Of course the first I made was to install the RC5 client in order to see how many keys/sec this box is able to perform. I was simply AMAZED: A 500 PIII with PIII (SIMD) optimized code delivered about 1.3Mega keys/sec. The PPC G4 delivered incredible 3.4 Mega keys/sec using the AltiVec optimized code, that is more that 2.5 times faster while running at about the same frequency as the PIII. I downloaded the AltiVec PDFs from http://www.altivec.org and checked out some interesting parts. The AltiVec engine does up to 4 x 32bit float ops / cycle. And there is even the multiply-add which does 4 multiplications and 4 additions within one cycle. That is a dream for us software-DSP folks. The really nice thing is that Motorola has even native C/C++ extensions (vector datatypes , and vector operations which get directly translated into altivec assemby instructions). look below for how simple it is to do a 4 way multiply-add which runs at full speed. ( d = vec_madd(a,b,c) ) And the nicest thing is that these C/C++ extensions exist as a gcc patch ! see here for some infos: http://www.terrasoftsolutions.com/news/2000-03-23.shtml I think the PPC G4 HW platform has really future in the studio from a raw MFLOPS POV. Can you imagine how beautiful it will be to have a PPC running on PPC-Linux with ALSA and soundcards like the Hammerfall ? But again the cross-platform capabilties of Linux will this make this transition quite easy ( port ALSA, recompile apps adding Altivec cores written in C/C++ (!!) without touching any assemby instruction, and ... continue working as usual ... but with the difference to running with 2-3 times your previous speed. :-) (Assume Steinberg ports Cubase/Nuendo for Linux/x86 , when it would be quite easy (if they paid attention to bigendian/littleendian issues)) to port the whole app to Linux/PPC since it would basically involve a recompile with some minor tweaks. Write once ... run anywhere (on any Linux platform at native speed) Now I know where to invest unneeded money: a Mac G4 :-) (but wipe out MacOS before :-) ) ----- Vector Multiply Add d = vec_madd(a,b,c) do i=0 to 3 d(i) := RndToFPNearest(a(i) * b(i) + c(i) ) end Each element of the result is the sum of the corresponding element of c and the product of the corresponding elements of a and b. ----- Benno.
