Multiprocessor system VS one processor system

[Lanny Baron]

Hi Erich,
Yes you are right. A Server Board cannot be changed with the expectation
that the system to still run.

But as I said, with real redundancy, as some of our customers do have,
such that if Server 1 died, Server 2 picks up immediately. The cost of
which, is substantially less than that of systems such as you imply.

Lanny

On Thu, 2004-03-18 at 23:46, Erich Dollansky wrote:
> Hi,
> 
> Lanny Baron wrote:
> 
> > On Thu, 2004-03-18 at 22:12, Erich Dollansky wrote:
> > 
> >>
> >>People tend to forget that the CPU clock rate of all Sun boxes is 
> >>pretty low but the I/O bandwith is much higher than the memory 
> >>bandwith of Xeon machine.
> >>
> >>Little things like changing a CPU while the machine is up and 
> >>running is not known to PC based servers at all.
> >>
> >>A PC based server is good when you have to consider the money but 
> >>will increase the risk of down-time.
> >>
> > 
> > 
> > That very strongly depends on what kind of pc Server you buy. 
> > 
> > A high quality Server with fully redundant power, dual or quad CPU's,
> > dual NICs, IPMI compliant, you will have one hell of a time showing me
> > downtime due to hardware. Yes, if the Server Board blows, it matters not
> > if it is a Sun<tm> or PC based. But then when it comes to mission
> > critical, a second lower cost or entry level Server as a backup or
> > failover will keep the 'lights on'.
> > 
> No. I have seen no PC based hardware yet which keeps the lights on 
> like the big machines. Even if a server board blows, the lights 
> stay on. Everything is at least double. You can also have it four 
> times in the box. It is just a matter of money.
> 
> You will read it in the newspapers when people think that they can 
> use PC based server in real mission critical applications.
> 
> > The thing here is, how well does a company stand behind its product and
> > how quickly (or slowly) will you get looked after is very important.
> > 
> The big machines just become slower because the failed hardware is 
> not there anymore but they are still up and running. A good 
> response time of the company behind brings only the performance 
> faster up to normal level.
> 
> As I said, it is the price you have to pay to get this. Those 
> machines cost much much more than PC based servers but they also 
> deliver what you need for real mission critical applications.
> 
> You just can't change a motherboard on a PC based machine while 
> the machine is running. You can change any component on the big 
> machines without any problems while the machine is up and running.
> 
> Erich
-- 
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Lanny Baron
Proud to be 100% FreeBSD
http://www.FreeBSDsystems.COM
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