From: Niche (jackyliu419@gmail.com)
Date: Mon Jun 11 2007 - 05:16:44 ART
/bow.. thank you very much for the explanation~
Cheers~
Jacky
On 6/11/07, Noel Bourke <cros13@gmail.com> wrote:
> Depends on what xeon models you are talking about, they can have varied
> architectures.
> The 3/5/7000 series xeons are based on the same architecture as the core 2
> with more cache.
> The 3.2Ghz xeon noncona's i use on my fixed dynamips system at home are
> essentially 64 bit prescott
> P4s with more cache (I havent been home since november, so no point in
> upgrading)
> I use a 2.33 core 2 in my laptop and run dynamips on that.
>
> Really there are so many generations and varients of xeon that there is
> little i can say that would be
> applicable to your question.
>
> There are some generalisations i can make.
> Xeons are always based on a consumer architecture (e.g. Xeon Noncona = P4
> Prescott,
> Xeon Paxville = PD Smithfield, Xeon Woodcrest = Core 2 Duo (Conroe) ) and
> they inherit
> mostly the performance and characteristics of the consumer arch on which
> they are based.
> Modern Xeons are basically dual/multi processor intact (on the consumer
> versions this is forced disabled)
> with extra cache (cache is expensive) and maybe a different pinout to help
> (force) you to buy a
> new motherboard with one of the expensive intel workstation chipsets.
> http://en.wikipedia.org/wiki/Xeon should explain the
> differences best.
>
> As to the choice.... your quad core consumer chip is really two core 2 duos
> packaged together.
> It will be cheaper, use less power, be more reliable, not force you to buy a
> chipset/motherboard combo
> you dont want or need for 5 times the price of a consumer board with the
> same features as far as your use goes,
> run at a higher fsb speed than any but the quad core xeon due to it being a
> kentsfield chip giving a slight bump in performance.
>
> In short there are plenty of reasons to go quad-core instead of xeon, and
> unless you are building a dual
> quad-core xeon rig (if you are tell me who pays you that much so i can
> replace you ;) ) there is really
> no reason to go xeon unless you like the logo and big bills.
>
> Regards,
> Noel
>
>
> On 6/11/07, Niche <jackyliu419@gmail.com> wrote:
> > Hi Noel,
> >
> > Just asking,
> >
> > 1. Intel Quad Core CPU
> > 2. Dual-Core Xeon x 2
> >
> > I know it's hard to do a direct comparison but let pick the closest
> > match for clock rate of the CPU for both setup. Which one will going
> > to provide the best performance? I was told by one of my friend that
> > Setup 2 will win.
> >
> > Cheers~
> > Jacky
> >
> > > Quoting Noel Bourke <cros13@gmail.com>:
> > > Core 2, no question. I'm simplifying a bit here
> > > with my explanation of why, and glossing over
> > > quite a few issues.
> > >
> > > Core 2 is a "four wide" architecture, meaning that
> > > it can issue four instructions per clock cycle.
> > > All of AMD's products are "3 wide". Predictability
> > > of instructions is crucial here to gain maximum
> > > benefit.
> > >
> > > Also due to the that emulation generates quite
> > > predictable instructions, dynamips benefits from a
> > > longer pipeline. This gives the core 2's 14-stage
> > > an advantage over the AMD 12-stage. Its also the
> > > reason why the 31-stage p4 (netburst) did so well
> > > with binary patching (e.g. VMware) and
> > > architecture emulation (e.g. PearPC).
> > >
> > > The Core2's dynamically allocated shared cache
> > > also helps. More cache can be used by a core
> > > running a dynamips process which is under greater
> > > load (e.g. emulating say a hub router, or a router
> > > running more protocols than the others). AMD has
> > > the hypertransport bus and onboard memory
> > > controller which is not as decisive an advantage
> > > as the core 2 cache.
> > >
> > > A dynamips can also be aware of data loaded to the
> > > cache by a process running on the other core which
> > > with a static image file like the ios image You
> > > are using with dynamips can reduce the amount of
> > > times the process has to access the drastically
> > > slower main memory.
> > >
> > > So to simplify a bit further, say your dynamips
> > > process on one core is running though the section
> > > of the ios image to send an ospf hello. 1.3
> > > seconds later another dynamips process running on
> > > the other core has to send a hello too, your AMD
> > > has to take a comparatively long commute to the
> > > memory controller (yes even though the memory
> > > controller is onboard its still further then the
> > > cache), and then an epic transcontinental journey
> > > to main memory. For all it cares your other cpu
> > > cores cache could be in siberia instead of right
> > > beside it on the die, its not even aware of its
> > > existence let alone contents. The AMD will
> > > probably have half or less cache then the core 2
> > > regardless.
> > >
> > > OK enough on the CPU. Core 2 it is then.
> > >
> > > RAM....uhuh....ok....go for the fastest you can
> > > get (PC5200+). no manufacturer or retailer i know
> > > of tells you any more specifics, such as timings
> > > so ignore the rest.
> > >
> > > As to amount of RAM....errr i'm going to say this
> > > later but any 32 bit OS is limited to 4GB of
> > > memory (excluding PAE but that isent relevant as 4
> > > GB 'aint the major barrier. On windows memory is
> > > handled pretty awfully. what happen when you have4
> > > gigs of memory is say for example on 32bit XP,
> > > each process is essentially limited to 1.8 gb.
> > >
> > > Last point, don't run dynamips on windows. Its
> > > running not quite natively on an architecture
> > > which bears little resemblence to the robust unix
> > > box it was designed for, which happens to have
> > > awful memory management, a bolted on network
> > > stack, pitiful management of multiple processors
> > > and multithreading that grinds to a halt when
> > > under load. thats not microsoft-bashing, windows
> > > is severely structurally flawed due to the bolting
> > > on of not just features but entire concepts (like
> > > multi-user and networking), both apply to
> > > dynamips.
> > >
> > > Linux will run daynamips with the same configs
> > > 10-20% faster on any processor. and it won't
> > > become unusable at 100% cpu usage because
> > > processes are pretty much forced to play nice.
> > >
> > > If you are voluntarily using dynamips on vista i'd
> > > call the nice doctors in the white coats or you
> > > could get a job far enough away from computers
> > > that you cant hurt them anymore.
> > >
> > > Do
> > > - use any 64bit distro of linux,
> > > - do download the source code from the dynamips site,
> > > - do compile using
> > > gcc 3.2+ using cpu specific optimisation
> > > and the -O3 option for threading,
> > > - do set your idle-pc correctly.
> > >
> > > I emulate up to 24 7200s simultaneously here on my
> > > laptop (2.33Ghz Core 2, 4GB Ram).
> > >
> > > Apologies for the quasi-religous ferver.
> > >
> > > Regards,
> > > Noel Bourke
> > >
> > > On 6/9/07, Con Spathas <con@spathas.net> wrote:
> > > >
> > > > Check out http://7200emu.hacki.at/
> > > >
> > > > This question has been asked many times there!
> > > >
> > > > Cheers...
> > > >
> > > > -----Original Message-----
> > > > From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On
> Behalf Of
> > > > lalit gupta
> > > > Sent: Saturday, 9 June 2007 08:19
> > > > To: Cisco certification
> > > > Subject: Maximum number of instances on dynamips/dynagen.u
> > > > I am planning to buy a laptop for running maximum number of
> instances on
> > > > dynamips/dynagen.
> > > >
> > > > Which configuration will you geniuses recommend.
> > > >
> > > > 1) AMD 64-bit process 2GHz
> > > > 2 GB RAM
> > > > or
> > > > 2) Core 2 Duo processor 2 GHz
> > > > 2 GB RAM
> > > >
> > > > Also will it help if I increase the RAM further more.
> > > >
> > > > Please if you can given any more information which will be
> useful please
> > > > don't hesitate to reply.....
> > > >
> > > > Regards
> > > > lalit
> > > >
> > > >
> _______________________________________________________________________
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> > >
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> > >
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