Mikus Grinbergs wrote: >I have not even looked at the specifications for the cell processor, >but from general reading I have the impression that what it is really >fast at is computing with 32-bit floating_point numbers. Doesn't >GIMPS need to use larger numbers than that? [I believe computation with >longer floating_point numbers is much slower on today's cell processor.] > >
Cell is a fast full featured 64bit PowerPC core with 8 satellite 'DSP' type processors on the same chip. Programming it is apparently quite a trip, since they have considerably different instruction set architectures, IBM and Sony have had to come up with some novel compilation tools to let you combine modules of the two different processors into one executable. http://www-306.ibm.com/chips/techlib/techlib.nsf/products/Cell_Broadband_Engine the DSP things (they call them SPE's) operate on 128 bit chunks which are two double floats, or two 64 bit ints, or 4 single floats or 4 32bit ints or 8 16bit... or 16 8bit... Each SPE has 128 128bit registers, and 256kbyte of local memory which is used for core and data. The ONLY access the SPE's have to main memory is via a DMA engine, which provides a globally coherent view of memory and utilizes the host processors MMU. The SPE's were totally designed for doing stuff like FFT's. Each SPE can dispatch up to 2 instructions per cycle at 7 execution units, with some tricky even/odd pipeline stuff. you can now get a Cell in a Blade system module that can be installed in a IBM BladeCenter... looks like they put two 3.2Ghz Cell's into a double wide Blade, so you can put 7 of these dual Cells into a 7U chassis (and probably 4KW of power :D). They have Fedora Core 5 based Linux running on the Power core which supports SPE programming. _______________________________________________ Prime mailing list [email protected] http://hogranch.com/mailman/listinfo/prime
