AMD64 impressions (Re: AMD64 box)

[Matthew Dillon <dillon@xxxxxxxxxxxxxxxxxxxx>]

    I was able to boot the AMD box with APMBIOS commented out (FreeBSD-4.x
    also can't boot the box with APMBIOS turned on either.  I'll test
    FreeBSD-current later today).

    I ran some preliminary buildworld benchmarks.  I don't have equivalent
    machines but a few things are obvious from the results:

    (1) The AMD box is very fast.  Very, very fast.  It blows away everything
	else hands down.  It is so fast that it spends nearly 1/3 of its
	time waiting on I/O despite the fact that the I/O requirements
	for a buildworld are fairly minimal.  It is so fast it makes my P4
	look like a snail, and even puts my DELL2550 (which is no slouch)
	to shame.

	The best comparison is the AMD box verse the P4 box.  Both are UP
	boxes.  The AMD box is 2.1x faster then the P4 box.  If clock speeds
	scaled, that would make the AMD box equivalent to 2.6GHz P4.  Since
	clock speeds don't scale, the AMD box is more like a 3.3GHz P4.

    (2) The AMD's syscall overhead is very low compared to the P4.
	I ran the 'sc1' test in /usr/src/test/sysperf.  The AMD box
	comes back at 242nS/loop while the P4 takes 1300nS/loop and
	the DELL box (LEAF/SMP) takes 617nS/loop.

    (3) I need to work on the SYS time for DragonFly SMP.  LEAF's SYS
	time should be around 400s, not 961s.  It's the SMP lwkt_token code
	being used for the vnode locks that is the likely culprit.  LEAF
	is a 2xCPU DELL-2550 and no slouch (not like VALinux 2xCPU box which
	is a piece of junk).  LEAF should have done better then it did.

						-Matt

    /usr/bin/time -l make -j 4 buildworld 	(of dragonfly's /usr/src)

(a) AMD Athlon(tm) 64 Processor 3200+ (2002.57-MHz 686-class CPU)
     Running DragonFly, UP build.  1 cpu.  (with two PC3200 512M sticks)

(b) Intel(R) Pentium(R) III CPU family      1133MHz (1125.77-MHz 686-class CPU)
     Running DragonFly, SMP build.  2 cpus. (PC133 SDRAM, but a fast DELL bus)

(c) Intel Pentium III (746.76-MHz 686-class CPU)
    Running FreeBSD-4.x, SMP build, 2 cpus. (PC133 SDRAM)

(d) Intel(R) Pentium(R) 4 CPU 1300MHz (1296.07-MHz 686-class CPU)
    Running FreeBSD-4.x, UP build, 1 cpu.  (with RDRAM)

(a)  1237.27 real       742.21 user       171.86 sys	1xAMD / DragonFly
(b)  1697.20 real      1370.54 user       961.67 sys	2xP3@xxxxxx / DragonFly
(c)  2271.17 real      2482.18 user       983.53 sys	2xP3@750MHz / FreeBSD
(d)  2656.12 real      1825.19 user       461.28 sys	1xP4@xxxxxx / FreeBSD