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Date:      Thu, 20 Feb 1997 18:40:51 -0600
From:      dkelly@hiwaay.net
To:        Bruce Evans <bde@zeta.org.au>
Cc:        hardware@FreeBSD.org
Subject:   Re: _big_ IDE disks? 
Message-ID:  <199702210040.SAA28380@nexgen.ampr.org>
In-Reply-To: Message from Bruce Evans <bde@zeta.org.au>  of "Thu, 20 Feb 1997 15:37:15 %2B1100." <199702200437.PAA19813@godzilla.zeta.org.au> 

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Bruce Evans writes:
>
> Run `dd if=/dev/zero of=/dev/null bs=1m count=1000' and complain if
> the throughtput is much lower than 120MB/sec.

nexgen: {366} uname -a
FreeBSD nexgen 2.2-GAMMA FreeBSD 2.2-GAMMA #0: Sat Feb  8 07:30:46 CST 1997 
    dkelly@nexgen.ampr.org:/usr/src/sys/compile/NEXGEN  i386
nexgen: {367} dd if=/dev/zero of=/dev/null bs=1m count=1000
1000+0 records in
1000+0 records out
1048576000 bytes transferred in 30.300733 secs (34605631 bytes/sec)

System is a "P90" NexGen Nx586, PCI. CPU ID's as a 386, and thats the way 
my kernel is compiled. Who do I complain to? :-)

OTOH, it does "make world" in just over 7 hours with its 64 bit wide bus. 
About the same as my super cheap AMD 5x86/133-P75 on a 32 bit wide bus.

Maybe I'm in the market for a new CPU/MB. What gives 120MB/sec performance? 
This is the $116 5x86/133 w/ 256k of write-thru cache:

PeeCee: {1001} dd if=/dev/zero of=/dev/null bs=1m count=1000
1000+0 records in
1000+0 records out
1048576000 bytes transferred in 24.782880 secs (42310498 bytes/sec)
PeeCee: {1002} uname -a
FreeBSD PeeCee.tbe.com 3.0-CURRENT FreeBSD 3.0-CURRENT #0: Wed Feb  5 
13:06:39 CST 1997     dkelly@PeeCee.tbe.com:/usr/src/sys/compile/PEECEE  
i386

PeeCee would probably beat NexGen in "make world" if I'd replace PeeCee's 
mode 0 IDE HD with NexGen's 2G narrow Barracuda.

mdsc1 102% hinv
1 100 MHZ IP20 Processor
FPU: MIPS R4000 Floating Point Coprocessor Revision: 0.0
CPU: MIPS R4000 Processor Chip Revision: 2.2

Hmdsc1 103% time dd if=/dev/zero of=/dev/null bs=1000k count=1000
1000+0 records in
1000+0 records out
0.0u 9.9s 0:10 97% 0+0k 0+0io 0pf+0w
mdsc1 104% expr 1048576000 / 10
104857600

Doggnone! Can't even get 120MB/sec out of a moderately old SGI Indigo! But 
much closer.

Hey, this was sorta fun. Time to dig out the 486dx33 and 386sx16.  :-)

--
David Kelly N4HHE, dkelly@hiwaay.net
=====================================================================
The human mind ordinarily operates at only ten percent of its
capacity -- the rest is overhead for the operating system.





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