Depends on the architecture. In an AMD opteron-based dual, each cpu has
a local memory controller and local memory, connected through the
hypertransport to the other processor through its hypertransport
interface. Both processors can access their own local memory with no
interference whatsoever. On a dual core, there is a single memory
controller, shared by two processors, leading to a potential bottleneck.
There is also a single hypertransport to get to other processors on
other chips, and that can also be a bottleneck.
But all in all, dual-cores are dynomite for performance, but one needs
to be careful to avoid the memory bottleneck...
Robert M. Hyatt, Ph.D. Computer and Information Sciences
hyatt@xxxxxxx University of Alabama at Birmingham
(205) 934-2213 136A Campbell Hall
(205) 934-5473 FAX Birmingham, AL 35294-1170
On Wed, 26 Apr 2006, Urs Thuermann wrote:
Bill Davidsen <davidsen@xxxxxxx> writes:
The bad part is that the cores share a bus connection, the good part
is that it appears that some IPC can be done on chip.
Why is that bad? Is that different from a dual CPU system? I thought
in a dual CPU system, too, both CPUs share the bus and only one CPU
can use the bus at a time (as long we're not talking about NUMA, of
course).
urs
-
: send the line "unsubscribe linux-smp" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
-
: send the line "unsubscribe linux-smp" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
