Re: Dual Core vs Dual CPU



On Thu, 29 Jun 2006 22:22:29 -0400, daytripper
<day_trippr@xxxxxxxxxxxxxxx> wrote:

On Fri, 30 Jun 2006 01:51:32 GMT, Barry Watzman <WatzmanNOSPAM@xxxxxxxxxx>
wrote:
Mark A wrote:
A dual CPU machine is always faster than a dual core.

This may not necessarily remain true. In a dual core machine, there can
be common cache memory connected to both CPUs that can be accessed FAR
faster than if there were two separate CPUs on two separate chips, and
the connections between them had to be over a bus with relatively
limited speeds and bandwidth. Dual core technology is evolving quickly,
and we will see quad-core systems within less than a year. They may
eclipse systems with multiple conventional CPUs.


Shared caches aren't 100% goodness. Thrashing, in particular, will be a more
frequent occurrence in a dual core/shared nth level cache configuration than
with two separate processors with their own nth level caches...

/daytripper

I kinda like two networked single core machines. If one crashes, it
doesn't make as big a mess.

Most everyone these days has a new machine and an old one.

.



Relevant Pages

  • Re: Dual Core vs Dual CPU
    ... be common cache memory connected to both CPUs that can be accessed FAR ... faster than if there were two separate CPUs on two separate chips, ... Dual core technology is evolving quickly, ...
    (alt.comp.periphs.mainboard.asus)
  • Re: New libc malloc patch
    ... > someone steps up to change the way mmap and brk interact within the ... > be allocated with brk. ... we already have systems running with enough CPUs that this is an issue. ... > address space and the cache: the mapping of logical pages (what you ...
    (freebsd-current)
  • Re: Purchasing the correct hardware: dual-core intel? Big cache?
    ... there's not enough IO to stress the disk subsystem. ... with more CPUs by getting true dual-core pentiums. ... The question this all pivots on is will 8M of cache be a significant ... We're looking hard at getting either Intel dual-core procs, ...
    (freebsd-questions)
  • Re: Purchasing the correct hardware: dual-core intel? Big cache?
    ... dual core is on average 20% faster than hyperthreaded CPU's. ... Poor optimization causes a CPU to chug along, flushing the CPU cache often, and slowing things down considerably. ... >>This message has been scanned for viruses and ... >>MailScanner thanks transtec Computers for their support. ...
    (freebsd-questions)
  • Re: Atmel releasing FLASH AVR32 ?
    ... a cache doesn't impact other accesses to non-cacheable ... Branch prediction cost is chasing an ever eluding target. ... There are few wasted cycles on modern embedded CPUs. ... Hardware multithreading doesn't give much performance on a high ...
    (comp.arch.embedded)