Re: a dozen cpu's on a chip

John Larkin wrote:
On Wed, 14 May 2008 09:17:16 +0100, Martin Brown
<|||newspam|||@nezumi.demon.co.uk> wrote:

John Larkin wrote:
On Tue, 13 May 2008 17:31:21 +0100, Martin Brown
<|||newspam|||@nezumi.demon.co.uk> wrote:

You really should investigate *why* your PCs are so unreliable rather than blathering on about how the world would be all sweetness and light if only Intel would make a 256 core CPU.

XP isn't bad, especially to people whose standards were lowered by '95
and '98. To people who used to run DEC timeshare systems, or who do
hard realtime stuff that may not have bugs, it's still pretty bad.

Remind me. Just how many CPUs did a VAX 11/780 have?
Hint: I know how many a 782 and 784 (exceedingly rare) had.
Google "VAX 784 problems field rework" shows a relevant summary as top hit although the actual page cached and pointed to has been sanitised. DEc had a lot of bother with the 784 and 785 was a faster single CPU.
Do you begin to see the fallacy of your argument?

Evidently not. VAX hit a brick wall for mainframe CPUs with N=4.

Blathering? Do you think that computer architectures are perfected,
and will never change? Do you think that all the multicore CPU's being
introduced will only be used to make things more complex and less
reliable?

For N>4 basically yes, unless very special circumstances apply that allow some of the CPUs to be dedicated to specific CPU intensive tasks or the problem has extremely high symmetry or is divisible in some other way that lends itself to spreading the load across many CPUs.

It will simply waste power and silicon to no good end in a general purpose PC. This doesn't mean it won't happen, but it will most likely be done to make some meaningless benchmark run faster.

Your idea is so bad and misguided as to be risible. If you cannot understand this then there is no point in continuing.


http://www.news.com/2100-1006_3-6119618.html

http://blogs.computerworld.com/node/6072

http://www.efluxmedia.com/news_Tilera_Unveils_64_core_CPU_07885.html

These are all fast multicore hardware designs intended for moderately exotic supercomputer type architectures and all admit that they will be pigs to program efficiently even with specialist tools. They do have their place but it isn't in general purpose desktop PCs.

Dvorak has vague inklings as to what's going on:

http://www.pcmag.com/article2/0,1895,2129596,00.asp

What you mean is he shares your naive misconceptions.

Time will demonstrate which of us is correct.

Regards,
Martin Brown
** Posted from http://www.teranews.com **
.

Relevant Pages

  • Re: LAN access while VPN is up
    ... > There is no AV on the bigger boxes, because they don't have the CPU ... > ASIC box vs a general purpose computer with an OS and software running on ... low-cost product and gained such market share in the first place. ...
    (comp.security.firewalls)
  • Re: a dozen cpus on a chip
    ... DEc had a lot of bother with the 784 and 785 was a faster single CPU. ... These are all fast multicore hardware designs intended for moderately ... their place but it isn't in general purpose desktop PCs. ...
    (sci.electronics.design)
  • Re: LAN access while VPN is up
    ... There is no AV on the bigger boxes, because they don't have the CPU ... And that's just single packet deep inspection, ... >> the advantages of an ASIC box vs a general purpose computer with an OS ... It's definately an oddball and took them a while to sort it out. ...
    (comp.security.firewalls)
  • Re: [Full-disclosure] Cisco IOS Shellcode Presentation
    ... > result of a specific architecture within the CPU chosen. ... of *any* general purpose processor implies these sorts of vulnerabilities. ... ABI on anything we'd consider a "general purpose CPU", ... are almost entirely operating system level stuff... ...
    (Full-Disclosure)
  • Re: [Full-disclosure] Cisco IOS Shellcode Presentation
    ... > Cisco is responsible for this entire mess. ... > product around a CPU that was not general purpose, ... something like a FPGA to emulate an ASIC, at the expense of cost. ...
    (Full-Disclosure)