[72964] in North American Network Operators' Group
Re: Quick question.
daemon@ATHENA.MIT.EDU (Paul Jakma)
Wed Aug 4 02:49:40 2004
Date: Wed, 4 Aug 2004 07:48:59 +0100 (IST)
From: Paul Jakma <paul@clubi.ie>
To: Alexei Roudnev <alex@relcom.net>
Cc: Michel Py <michel@arneill-py.sacramento.ca.us>,
Nanog <nanog@nanog.org>
In-Reply-To: <004101c479e8$2a2e0890$6401a8c0@alexh>
Errors-To: owner-nanog-outgoing@merit.edu
On Tue, 3 Aug 2004, Alexei Roudnev wrote:
> In theory, yes. On pracrtice, 2 CPU improve behavior dramatically.
That is not about reliability. That's to do with software
performance.
I was purely picking a, admittedly pedantic, nit with the notion that
SMP == more reliable. I'm not trying to argue that SMP does not have
other benefits (eg performance).
> 4 CPU makes system too complex (as you wrote beloow).
Nah, the big jump in complexity appears to be from no-concurrency to
concurrency. After that initial hurdle, 2 to 4 to 8 CPUs isnt as big
a deal (making it scale is though).
> New P-IV with multi threading may be a good selection - behave as 2
> CPU system but is not so complicated as SMP.
From the OS POV, the complication is the same. And yes, even
single-processors are today capable of presenting multiple execution
contexts to software, and it seems to be a trend we'll see more and
more of.
> In reality, applications are less reliable on 2 CPU systems (if
> they have some kinds of bugs, which make sense on SMP only), so I
> agree with you in some cases.
Right..
regards,
--
Paul Jakma paul@clubi.ie paul@jakma.org Key ID: 64A2FF6A
Fortune:
Rubber bands have snappy endings!
