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Date:      Sun, 4 Mar 2001 01:34:17 -0800 (PST)
From:      Matt Dillon <dillon@earth.backplane.com>
To:        freebsd-hackers@freebsd.org
Subject:   Machines are getting too damn fast
Message-ID:  <200103040934.f249YHi27877@earth.backplane.com>
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    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.

    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.

    Sony 1.3 GHz Pentium 4 VAIO w/ 128MB RamBus memory (two 64MB RIMMs)
	571.20 MBytes/sec (copy)

    650 MHz Celleron (HP desktop, DIMM)
	114.65 MBytes/sec (copy)

    750 MHz P-III (2U VALINUX box, 2-cpu, 1024M ECC-DIMM)
	162.20 MBytes/sec (copy)

    700 MHz Celeron(?) (1U VALINUX box, 1-cpu, 128MB DIMM)
	93.56 MBytes/sec (copy)		<---- yuch

    550 MHz P-III (4U Dell 2400, 1-cpu, 256MB DIMM)
	225.92 MBytes/sec (copy)

    600 MHz P-III (2U Dell 2450, 2-cpus, 512MB DIMM))
	228.91 MBytes/sec (copy)

    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 
    more RamBus memory for the thing (it only came with 128MB), which is 
    kinda of annoying seeing as I have a gigabyte worth of DIMMs just sitting
    on my desk :-( that I can't use.

    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.

    We need to find something more interesting then buildworlds to do on
    these machines.

						-Matt


/*
 * Attempt to test memory copy speeds.  Use a buffer large enough to
 * defeat the on-cpu L1 and L2 caches.
 */

#include <sys/types.h>
#include <sys/time.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include <unistd.h>

#define NLOOP	100

char Buf1[2 * 1024 * 1024];
char Buf2[2 * 1024 * 1024];

int deltausecs(struct timeval *tv1, struct timeval *tv2);

int
main(int ac, char **av)
{
    int i;
    double dtime;
    struct timeval tv1;
    struct timeval tv2;

    memset(Buf1, 1, sizeof(Buf1));
    for (i = 0; i < 10; ++i)
	bcopy(Buf1, Buf2, sizeof(Buf1));

    gettimeofday(&tv1, NULL);
    for (i = 0; i < NLOOP; ++i)
	bcopy(Buf1, Buf2, sizeof(Buf1));
    gettimeofday(&tv2, NULL);

    dtime = (double)deltausecs(&tv1, &tv2);
    printf("%6.2f MBytes/sec (copy)\n", (double)sizeof(Buf1) * NLOOP / dtime);
    return(0);
}

int
deltausecs(struct timeval *tv1, struct timeval *tv2)
{
    int usec;

    usec = (tv2->tv_usec + 1000000 - tv1->tv_usec);
    usec += (tv2->tv_sec - tv1->tv_sec - 1) * 1000000;
    return(usec);
}


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