Extreme Multithreading on a Chip 29
kid writes "There's an interesting interview with Dr. Marc Tremblay at Ace's Hardware. Dr. Tremblay is a distinguished engineer at Sun and the co-architect of the UltraSPARC processor. He is currently working on a processor that is claimed to deliver 30 times the performance of current CPUs utilizing an agressive multi-core/multi-threaded architecture. He talks about upcoming highly multithreaded CPUs from Sun as well as a wide range of problems facing today's CPU designers, from branch mispredictions to DRAM latency/bandwidth and power dissipation, and the ways in which he is working on solving them."
eXtreme multithreading? (Score:2, Funny)
Re:eXtreme multithreading? (Score:1)
Re:eXtreme multithreading? (Score:2)
Hard to program? (Score:4, Interesting)
That being said, multi-threaded processing certainly speeds up an OS. BeOS is by far the fastest OS i've ever used.
Re:Hard to program? (Score:5, Informative)
There's no speed magic to multithreading on a single thread single CPU system - actually, preemptive multitasking can only reduce raw CPU power.
For desktop systems, responsiveness is far more important than raw speed - but Sun is in the server business, in which desktop-style responsiveness is less important.
Furthermore, do not confuse CPU threads with O/S threads; CPU threads may just as well run distinct processes which have no relation to each other - in fact there are architectures that use this as an advantage and do away with a memory cache.
Multiple threads make software hard to develop (and to debug and test). Multiple processes, essentially threads without a shared address space, much less so. Assuming, of course, that the address space is NOT shared....
Re:Hard to program? (Score:2)
Multiple threads make software hard to develop (and to debug and test). They can be sporting if you are sloppy (or someb
Re:Hard to program? (Score:2)
Consider that they are going to face competition from two sources. The first is Linux whose desktop offerings, while still weak, are light years ahead of Sun. Even if Sun largely borrows Redhat's playbook and adds a bit more, they still have the hardware problem. They need cheap chips that are fast. They are competing with fast, cheap PC systems that run a desktop environment superior to anything Sun is likely to
Re:Hard to program? (Score:3, Insightful)
That's true, but threads are just as important on the server. With the exception of serving read-only data (e.g. web servers, DNS servers), server applications rarely fit into the independent-address-space model. As soon as a client can modify state that others may want (and assuming you need multiprocessor scalability, of course) threads
Re:Hard to program? (Score:2)
IBM too I think... (Score:2)
Anyone seen something relevant?
Cluster? (Score:3, Funny)
Tera Multithreaded computer (Score:2, Informative)
http://www.supercomp.org/sc98/TechPapers/sc98_F
to see about the Tera Multithreaded computer. 128 hardware threads per single cpu. It was interesting and was actually built (I saw a few).
Re:Tera Multithreaded computer (Score:1)
So what had to happen happened [npaci.edu].
Still, Teras were really cool machines. Sigh...
Intel (Score:3, Interesting)
It is nice to see that (non-super-computing) people finally come to the conclusion that clock speed isn't everything. All students studying computer architecture learns about the help of parallel tasks. Yet it seems as if everything has been about MHz and GHz the last ten-fifteen years. This is probably not due to the engineers, but rather, due to the Intel marketing department. What surprises me is how many engineers that followed...
Re:Intel (Score:1)
If you crank up MHz (or instructions per cycle), then every already wruten application can make use of them.
If you impose a multithreaded standard for programming to improve performance, well, fine, but it is maybe not simpler to rewrite your existing program : either you improve all(cpu-bound) programs by 100% (doubling processing speed for same arch) or you can multiply by 10 1% of the applications. The first one is more effective in the whole scale.
Of course, when you
Re:Intel (Score:2)
The thing is that most modern OSs runs more than one task at a them. Just try "ps -a" on your Linux box, or Ctrl-Alt-Delete, Task Manager on you Windows machine and look. Now, don't tell me that architectures that allow several processes to share the CPU have been obsolete up 'till now.
My guess is that the GHz have far more to do with marketing as that is the field where Intel beats AMD. Performance wise AMD has fought of Intel pretty well running at lower frequencies executing Intel-x86-compatible binarie
Compiler support is the flaw (Score:2)
Re:Compiler support is the flaw (Score:2)
Chris Rijk [Ace's Hardware]: And that's entirely hardware based -- does not need any special compilation or software support?
Dr. Marc Tremblay: That's correct.
Re:Compiler support is the flaw (Score:2)
AFAIK, if you wanted to use MMX instructions, you had to hand-code the operation yourself in asm. Correct me if I'm mistaken.
Re:Compiler support is the flaw (Score:1)
Re:Compiler support is the flaw (Score:1)
Re:Compiler support is the flaw (Score:2)
Re:Compiler support is the flaw (Score:2)
Sun Workshop (now Forte (now Sun ONE Compiler Suite)) should not be a problem. Sun's compiler has thorough support from generic SPARC v9 output to specific USIII/VIS output. When the USIV comes out, the next version of the compiler will simply have new command-line switches.
Additionally, th
SPARC: overpriced, underpowered (Score:1)