[GRLUG] virtual box/cpu speed"

[Bob Kline]

Not sure what's meant by the sweet spot
being at three processors.  Why?

A couple of observations.  Processors with six
CPUs have been available at popular
prices for a while now.  I take it if the sweet
spot is three, then the incremental performance
by having six is less than 2X - how much less?

The taskset command sets an affinity for a
CUP, which I take it is short of actually
being able to assign a process to a CPU,
and might be that way because one is competing
with the Linux scheduler.  But where physical
CPUs are actually available, isn't taskset a
way of taking advantage of an arbitrary number
of CPUs? i.e., performance doesn't actually
plateau as one adds CPUs?  That would be
true, if true at all, as long as there are always
enough processes that need a CPU.

So, again, what does a sweet spot of three
CPUs mean?

   -- Bob


On Wed, Mar 23, 2011 at 11:21 PM, Michael Mol <mikemol at gmail.com> wrote:

> Sure, there's a speedup with quad-core. Your computer has dozens of
> processes, and the ability to service more at the same time reduces latency.
>
> Additionally, some server services scale very well to multiple cores.
> HTTPd, for example. If you use soft RAID on Linux, and have the appropriate
> kernel option enabled, checksum calculations for RAID modes 4, 5, and 6 will
> be split across your cores.
>
> Desktop apps are catching up, too. If you use Firefox, Flash is kept as a
> separate process, a scenario which benifits from more cores (see my note on
> latency near the beginning). If you use Chrome or Chromium, each _tab_ is a
> separate process, which leverages multicore for app-wide performance
> improvements.
>
> These days, hanging at two cores when looking at making a purchase doesn't
> make sense.
>
> Right now, I believe the price/performance sweet spot is at three cores. It
> will probably be at four by the end of summer.
> On Mar 23, 2011 10:25 PM, "west mi" <west.mi420 at gmail.com> wrote:
> > Do you think there is a significant speed difference between the dual and
> > quad core cpu's?
> > I havent used anything but single and dual cores.
> > I switched several years back to dual core, and did notice a significant
> > speed up.
> >
> > Do you think vbox can fully utilize a quad core?
> > I hesitate on going to a quad core, because I don't know if today's
> software
> > can
> > fully utilize 4 cores.
> >
> > thanks,
> > Darrin
> >
> > On Wed, Mar 23, 2011 at 11:55 AM, Topher <topher at codeventure.net> wrote:
> >
> >> On Wed, 23 Mar 2011, west mi wrote:
> >>
> >> Anyone have win7 working in vbox?
> >>> And does it work good?
> >>>
> >>
> >> I'll chime in.
> >>
> >> I have a 32bit win7 install on my 32bit Arch linux laptop. The host has
> 2G
> >> of ram and I give one to the vm. I use Photoshop in it and it works just
> >> fine.
> >>
> >> I copied that vm to my 64bit arch host and that went flawlessly. Now
> that
> >> vm has 2G of its own, and 2 of my 4 processors. Still using photoshop,
> but
> >> it screams right along. It takes 5-7 seconds to go from power on to
> login,
> >> and maybe 12 seconds to reboot.
> >>
> >> I really like VirtualBox.
> >>
> >> topher
> >>
> >>
> >> --
> >> This message has been scanned for viruses and
> >> dangerous content by MailScanner, and is
> >> believed to be clean.
> >>
> >> _______________________________________________
> >> grlug mailing list
> >> grlug at grlug.org
> >> http://shinobu.grlug.org/cgi-bin/mailman/listinfo/grlug
> >>
> >
> > --
> > This message has been scanned for viruses and
> > dangerous content by MailScanner, and is
> > believed to be clean.
> >
>
> --
> This message has been scanned for viruses and
> dangerous content by *MailScanner* <http://www.mailscanner.info/>, and is
> believed to be clean.
> _______________________________________________
> grlug mailing list
> grlug at grlug.org
> http://shinobu.grlug.org/cgi-bin/mailman/listinfo/grlug
>

-- 
This message has been scanned for viruses and
dangerous content by MailScanner, and is
believed to be clean.

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://shinobu.grlug.org/pipermail/grlug/attachments/20110324/285778b5/attachment-0001.html>