Date: Sun, 4 Mar 2001 23:03:42 -0500 From: Coleman Kane <cokane@freebsd.org> To: Matt Dillon <dillon@earth.backplane.com> Cc: freebsd-hackers@freebsd.org Subject: Re: Machines are getting too damn fast Message-ID: <20010304230342.A3870@cokane.yi.org> In-Reply-To: <200103040934.f249YHi27877@earth.backplane.com>; from dillon@earth.backplane.com on Sun, Mar 04, 2001 at 01:34:17AM -0800 References: <200103040934.f249YHi27877@earth.backplane.com>
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You should see what speed RamBus they were using, 600 or 800 Mhz. It is
pretty fast for large memory writes and reads. It'd be cool to see how
the different speeds stack up against one another. DDR comparisons would
be cool too. Yeah, for the frequency, you have to take into account that
these are different chips than your PIII or Athlons and the performance
difference is not simply a linear relation to the frequency rating
(i.e.: 1.3Ghz is not really over one-billion instructions per second,
just clocks per second). We installed Linux at a UC Free OS User Group
installfest here in cincinnati, it was pretty sweet. The machine was a
Dell and the case was freakin' huge. It also came with a 21" monitor and
stuff. The performace was really good, but not really any better than I
hads gleaned from the newer 1Ghz Athlons or PIII's.
Matt Dillon had the audacity to say:
>=20
> I was browsing CompUSA today and noticed they were selling Sony
> VAIO 1.3 and 1.5 GHz desktops, amoung other things. It's amazing
> how fast processors have gotten just in the last two years! I just
> had to pick up one of these babies and give it a run through to see
> how fast the RamBus memory is.
>=20
> I'm suitably impressed, at least when comparing it against other Intel
> cpu's. Intel is finally getting some decent memory bandwidth. I've
> included some memory copying tests below. The actual memory bandwidth
> is 2x what the test reports since it's a copy test.
>=20
> Sony 1.3 GHz Pentium 4 VAIO w/ 128MB RamBus memory (two 64MB RIMMs)
> 571.20 MBytes/sec (copy)
>=20
> 650 MHz Celleron (HP desktop, DIMM)
> 114.65 MBytes/sec (copy)
>=20
> 750 MHz P-III (2U VALINUX box, 2-cpu, 1024M ECC-DIMM)
> 162.20 MBytes/sec (copy)
>=20
> 700 MHz Celeron(?) (1U VALINUX box, 1-cpu, 128MB DIMM)
> 93.56 MBytes/sec (copy) <---- yuch
>=20
> 550 MHz P-III (4U Dell 2400, 1-cpu, 256MB DIMM)
> 225.92 MBytes/sec (copy)
>=20
> 600 MHz P-III (2U Dell 2450, 2-cpus, 512MB DIMM))
> 228.91 MBytes/sec (copy)
>=20
> I was somewhat disappointed with the VALINUX boxes, I expected them to
> be on par with the DELLs. In anycase, the Sony VAIO workstation with
> the RamBus memory blew the field away. The cpu is so fast that a
> buildworld I did was essentially I/O bound. I'll have to go and buy =
some=20
> more RamBus memory for the thing (it only came with 128MB), which is=
=20
> kinda of annoying seeing as I have a gigabyte worth of DIMMs just sit=
ting
> on my desk :-( that I can't use.
>=20
> I'm tring to imagine 1.3 GHz. That's over a billion instructions
> a second. And in a few years with the new chip fab lithography
> standards it's going to be 10 GHz.
>=20
> We need to find something more interesting then buildworlds to do on
> these machines.
>=20
> -Matt
>=20
>=20
> /*
> * Attempt to test memory copy speeds. Use a buffer large enough to
> * defeat the on-cpu L1 and L2 caches.
> */
>=20
> #include <sys/types.h>
> #include <sys/time.h>
> #include <stdio.h>
> #include <stdlib.h>
> #include <stdarg.h>
> #include <unistd.h>
>=20
> #define NLOOP 100
>=20
> char Buf1[2 * 1024 * 1024];
> char Buf2[2 * 1024 * 1024];
>=20
> int deltausecs(struct timeval *tv1, struct timeval *tv2);
>=20
> int
> main(int ac, char **av)
> {
> int i;
> double dtime;
> struct timeval tv1;
> struct timeval tv2;
>=20
> memset(Buf1, 1, sizeof(Buf1));
> for (i =3D 0; i < 10; ++i)
> bcopy(Buf1, Buf2, sizeof(Buf1));
>=20
> gettimeofday(&tv1, NULL);
> for (i =3D 0; i < NLOOP; ++i)
> bcopy(Buf1, Buf2, sizeof(Buf1));
> gettimeofday(&tv2, NULL);
>=20
> dtime =3D (double)deltausecs(&tv1, &tv2);
> printf("%6.2f MBytes/sec (copy)\n", (double)sizeof(Buf1) * NLOOP / dt=
ime);
> return(0);
> }
>=20
> int
> deltausecs(struct timeval *tv1, struct timeval *tv2)
> {
> int usec;
>=20
> usec =3D (tv2->tv_usec + 1000000 - tv1->tv_usec);
> usec +=3D (tv2->tv_sec - tv1->tv_sec - 1) * 1000000;
> return(usec);
> }
>=20
>=20
> To Unsubscribe: send mail to majordomo@FreeBSD.org
> with "unsubscribe freebsd-hackers" in the body of the message
>=20
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