To: DiViT who wrote (35281 ) 8/19/1998 9:29:00 PM From: Ron Mayer Read Replies (1) | Respond to of 50808
VLIW vs SMP vs SIMD David wrote: ' [quoting someone] "The future is all about parallelism, and there are easier ways to get parallelism than to build a complex [VLIW] machine ... In short, it's better to have two simple machines than one complex one. I think it's absolutely clear we will move to SMP on a chip ." ... Furthermore, Cube tossed out the VLIW based encoder last year in favor of a Sparc based one.' But is it SMP? Or 'just' fast. If not, iCompression may be one of the more interesting MPEG companies doing SMP-on-a-chip: icompression.com : "Two on-chip digital signal processors. They execute Java(TM) Virtual Machine instructions." This is interesting because the well-defined multithreading specification seems to have put a lot of consideration into SMP-systems (did you ever read the parts of the JVM spec that refer to read,load,use,assign,and store operations and how they interact with shared "main memory" and thread-specific "working memory"). Of course it's arguable of whether or not Java has enough disadvantages in real-time-systems to make up for that benefit. . I believe both SMP and VLIW techniques have very interesting potential, and which is better may be application dependant: Note that Texas Instruments quite effectively uses both approaches: ti.com "TMS320C6x DSP ...(VLIW) architecture to achieve high performance through increased instruction-level parallelism" ti.com "TMS320C80, is a single-chip, parallel processor that can be used for applications such as real-time audio/video processing..." . However for most applications I'm still not convinced either SMP-on-a-chip or VLIW will be more cost-effective than RISC or DSP with SIMD extentions (like Intel's MMX or Sun's VIS) and special purpose hardcoded logic where extreme perfomance is needed. Anyone have any differing opinions? Anyone know which companies favor which kind of architure (VLIW, SMP-on-a-chip, SIMD, etc)? These are my guesses: Phillips: vliw eet.com C-Cube: vliw first, now risc (sparc)+hardcoded-logic? Message 5537340 iCompression: smp (2-java-cores)? icompression.com Chromatics: vliw first, now changed to smp Message 5537150 IBM: ? TI: vliw AND smp products targeted for digital video eetimes.com ti.com Intel RISC + DSP-like, dual-issue media processor eet.com Equator vliw Message 4618302 Innovacom :-) systolic arrays? Message 797091 Any corrections/additions?