[dundee] Opinions on the Sun Ultra 24 Box - Good bang-per-buck?

[Andrew Clayton]

On Fri, 25 Apr 2008 11:38:19 +0100, Rick Moynihan wrote:

> 2008/4/25 Andrew Clayton <andrew at digital-domain.net>:
> > On Thu, 24 Apr 2008 22:54:29 +0100 (BST), Lee Hughes wrote:
> >
> >  > yeah, but will the software (os/app's) take advantage of all that
> >  > threading capability?
> >
> >  I'll use the terms cores and cpu's interchangeably below..
> >
> >  Of course. Linux itself is quite capable of dealing with many
> > cpu's, with support for 4096 cpu's currently being worked on for
> > merging from the folks at SGI.
> >
> >  You want real world examples,
> >
> >  Compiling is an obvious one with make supporting parallel compiling
> >  natively, e.g make -j <num cpu's + 1>
> >
> >  If you use a source based distribution, you'll like many cores...
> >
> >  Saw a recent reference to an IBM machine that does 3K/sec (that's 3
> >  kernel builds a second)
> >
> >  Grip supports multiple cpu's for encoding audio.
> >
> >  I'm sure games will start supporting multiple cores, in fact IIRC
> > some version of quake does/did.
> >
> >  Any java app you use...
> >
> >  And just having the capacity that comes from having multiple cores,
> >  video encoding not interfering with your compilation for example.
> >
> >  That heavy javascript site causing firefox to hammer one of your
> > cores.
> >
> >  So yeah, Linux has been ready for this for a long time and as
> > multiple cores become more prevalent, I'm sure more apps will be
> > written specifically to take advantage.
> 
> This is all true, but with the current state of hardware  (at least
> under x86) I suspect that simply adding more CPUs & cores leads
> diminishing returns, due to problems with shared memory; i.e. cache
> and memory flushes under the hood.  Sure an 8/16 core machine sounds
> great, but I'm not sure if I could ever keep all the cores busy during
> my normal workload.

Yeah, It can depend on what your doing, long running cpu
intensive jobs probably make the most efficient use of multiple
cores/cpu's.

And I was just reading this thread,
http://www.ussg.iu.edu/hypermail/linux/kernel/0804.2/3300.html

"I have 128 cpus, that's 128 grabs of that spinlock every quantum. My
next system I'm getting will have 256 cpus."

> A single quad-core CPU where each core screams speed, seems like a
> better investment than going for 2 processors.  The question is

Yes, a quad core is likely better than 2 single core processors.