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Date:      Tue, 06 Apr 1999 23:09:14 -0700
From:      Darren Pilgrim <dpilgrim@uswest.net>
To:        Greg Lehey <grog@lemis.com>
Cc:        unknown@riverstyx.net, Mark Ovens <marko@uk.radan.com>, Leif Neland <leif@neland.dk>, FreeBSD Questions <questions@FreeBSD.ORG>
Subject:   Re: K6-2/333, was: Re: Debug kernel by default (was: System sizewith-g)
Message-ID:  <370AF68A.32DC11EF@uswest.net>
References:  <Pine.LNX.4.04.9904051744500.31071-100000@hades.riverstyx.net> <3709EE06.77F97B9E@uswest.net> <19990407142436.D2142@lemis.com>

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Greg Lehey wrote:
> On Tuesday,  6 April 1999 at  4:20:38 -0700, Darren Pilgrim wrote:
>> unknown@riverstyx.net wrote:
>>> On Mon, 5 Apr 1999, Darren Pilgrim wrote:
>>>> unknown@riverstyx.net wrote:
>>>>> I may be out to lunch on this one, but I'm pretty sure that the multiplier
>>>>> is for the internal clock of the chip.  So, if, after applying the
>>>>> multiplier to one chip you get 300MHz, and after applying a different
>>>>> multiplier to a different chip with a different bus speed you also get
>>>>> 300MHz, you get two chips that perform the exact same number of
>>>>> operations/sec.  The difference is the bus speed, which affects I/O
>>>>> performance, etc.  A 100 MHz bus with a x3 multiplier will outperform a 66
>>>>> MHz bus with a x4.5 multiplier because the CPU will have to wait more
>>>>> often when it wants to fetch non-cached data from RAM.
>>>>
>>>> While this is mathematically and theoretically sound thinking, tests
>>>> have shown that there is little CPU/memory performance gain with a
>>>> 100MHz bus.  Just take a look at www.tomshardware.com.  As for my own
>>>> systems, I run K6-2 333s at 5x66 just because it sets the PCI and AGP
>>>> clocks at their spec'd rate of 33 and 66MHz, respectively, while
>>>> providing the CPU's spec'd 333MHz.
>>>
>>> I've seen good speed gains by moving to a 100MHz bus, although this was
>>> for servers that were doing a lot of database work and heavy network
>>> traffic.  Perhaps it wouldn't matter much for servers doing more
>>> calculation-intensive work?
>>
>> Aye, in a server setup a faster bus does make a difference, but my
>> reference (Tom's HW) is for workstations.  Did I miss the first part
>> of the thread, was this discussion about servers?  If so, my apologies
>> for my misunderstanding.
> 
> No, we're not talking about artificial concepts like servers and
> workstations, we're talking about the low-level behaviour of the
> processor and memory.

Ah, okay then.  I did misunderstand, but I misunderstood what I was
misunderstanding.

>> Disk and memory work in a server can max a slower FSB, but if the
>> server is being used for CPU-intensive work, then what's the point
>> of spending extra for a server?
> 
> I'm not sure I understand this statement.

It's been my experience that you can save money if you build a
workstation for specific types of tasks, where are servers are best
suited to mixed environments where top performance in every aspect is
critical.  I could be wrong, it's not unheard of.

-- 
dpilgrim@uswest.net           /\  / __         Our lies are merely the
gryph@mindless.com           /  \/OC/URNE       truth of another world
ICQ: 29880099       Death is not a kill -9, just a                    
DALnet: anim0s      make world and shutdown -r now    PGPKey available


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