Date: Tue, 6 Mar 2001 15:40:25 -0500 From: "Brandon Gale" <bgale@targetnet.com> To: "Kenneth D. Merry" <ken@kdm.org>, "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: <BBEFKIOENNNDEEHMOMHOMEODGPAA.brandon@targetnet.com> In-Reply-To: <20010306110754.A23400@panzer.kdm.org>
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This explained in great detail exactly why people are seeing the performance they are from the P4 etc. The author knows his stuff. http://www.emulators.com/pentium4.htm Brandon :-----Original Message----- :From: owner-freebsd-hackers@FreeBSD.ORG :[mailto:owner-freebsd-hackers@FreeBSD.ORG]On Behalf Of Kenneth D. Merry :Sent: Tuesday, March 06, 2001 1:08 PM :To: Andrew Gallatin :Cc: Matt Dillon; freebsd-hackers@FreeBSD.ORG :Subject: Re: Machines are getting too damn fast : : :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 : :To Unsubscribe: send mail to majordomo@FreeBSD.org :with "unsubscribe freebsd-hackers" in the body of the message : To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
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