Date: Tue, 6 Mar 2001 11:07:55 -0700 From: "Kenneth D. Merry" <ken@kdm.org> To: Andrew Gallatin <gallatin@cs.duke.edu> Cc: Matt Dillon <dillon@earth.backplane.com>, freebsd-hackers@FreeBSD.ORG Subject: Re: Machines are getting too damn fast Message-ID: <20010306110754.A23400@panzer.kdm.org> In-Reply-To: <15013.2238.953211.516979@grasshopper.cs.duke.edu>; from gallatin@cs.duke.edu on Tue, Mar 06, 2001 at 10:56:46AM -0500 References: <Pine.BSF.4.32.0103051729350.84853-100000@mail.wolves.k12.mo.us> <200103060013.f260DHY46910@earth.backplane.com> <15013.2238.953211.516979@grasshopper.cs.duke.edu>
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On Tue, Mar 06, 2001 at 10:56:46 -0500, Andrew Gallatin wrote:
> Matt Dillon writes:
> >
> > I modified my original C program again, this time to simply read
> > the data from memory given a block size in kilobytes as an argument.
> > I had to throw in a little __asm to do it right, but here are my results.
> > It shows about 3.2 GBytes/sec from the L2 (well, insofar as my
> > 3-instruction loop goes), and about 1.4 GBytes/sec from main memory.
> >
> >
> > NOTE: cc x.c -O2 -o x
> >
> > ./x 4
> > 3124.96 MBytes/sec (read)
> <...>
> > ./x 1024
> > 1397.90 MBytes/sec (read)
> >
> > In contrast I get 1052.50 MBytes/sec on the Dell 2400 from the L2,
> > and 444 MBytes/sec from main memory.
> >
>
> FWIW: 1.2GHz Athlon, VIA Apollo KT133 chipset, Asus A7V motherboard,
> (PC133 ECC Registered Dimms)
>
> ./x 4
> 2393.70 MBytes/sec (read)
> ./x 8
> 2398.19 MBytes/sec (read)
> <...>
> ./x 1024
> 627.32 MBytes/sec (read)
>
>
> And a Dual 933MHz PIII SuperMicro 370DER Serverworks HE-SL Chipset
> (2-way interleaved PC133 ECC Registered DIMMS)
>
> ./x 4
> 1853.54 MBytes/sec (read)
> ./x 1024
> 526.19 MBytes/sec (read)
Dell Precision 420 (i840 chipset) with a single PIII 800 and probably one
RIMM, unknown speed:
{rivendell:/usr/home/ken/src:76:0} ./memspeed 4
1049.51 MBytes/sec (read)
{rivendell:/usr/home/ken/src:77:0} ./memspeed 1024
378.41 MBytes/sec (read)
The above machine may not have been completely idle, it seems a little
slow.
Dual 1GHz PIII SuperMicro 370DE6 Serverworks HE-SL chipset, 4x256MB PC133
ECC Registered DIMMs:
{gondolin:/usr/home/ken/src:51:0} ./memspeed 4
1985.95 MBytes/sec (read)
{gondolin:/usr/home/ken/src:52:0} ./memspeed 1024
516.62 MBytes/sec (read)
> There's something diabolic about your previous bw test, though. I
> think it only hits one bank of interleaved ram. On the 370DER it gets
> only 167MB/sec. Every other bw test I've run on the box shows copy
> perf at around 260MB/sec (Hbench, lmbench). I see the same problem on
> a PE4400 (also 2-way interleaved); it shows copy perf as 111MB/sec.
> Every other test has it at 230MB/sec.
The previous test showed about 270MB/sec on my Serverworks box:
{gondolin:/usr/home/ken/src:53:0} ./memory_speed
269.23 MBytes/sec (copy)
Ken
--
Kenneth Merry
ken@kdm.org
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