Re: [PD] 64 bit PD

By 'move' do you mean process calculations on the CPU? You would be describing SIMD and really bad MMX style SIMD at that. Modern CPUs have 128 bit wide vector units like Altivec and SSE which are fantastic if actually used.

the main question is, what can the compiler actually do with the hardware ... i'm not familiar with the amd64 architecture, but i suppose it's similar to simd instructions ...

• to use them, the memory regions have to be aligned ... otherwise it would not take the optimum of one command move data from memory to registers
• it can only be used if algorithms _can_ be vectorized ... that's not a problem with simple multiplications, but complex algorithms like filters, or interpolation algorithms will not take advantage of that...
• and the compiler will have to know the instructions and _use_ them ... as for now i can say that any compiler i tried (gcc 3.2/3.3, icc) had problems generating the optimal sse instructions ... (this is possibly related to dsp block allocation as it's done in pd at the moment)

that's why i somehow doubt that 64bit processors will bring a huge speedup for dsp algorithms ...

cheers ... tim