[AIM] UP vs SMP comparison

[Marcel Moolenaar]

All,

Below the "make buildworld" times ran on an UP and a SMP
kernel:

		UP	SMP
	-j1	5:09	5:31
	-j2	5:05	3:12
	-j4	5:07	3:04

Conclusions:
	o  It appears that CPU is the bottleneck for UP in my setup.
	o  An SMP kernel is 7% slower than an UP kernel.
	o  There's a 1.7x speed-up between -j1 and -j2 for SMP.

machine:
	FreeBSD 8.0-CURRENT #16 r183030:183060M: Mon Sep 15 23:16:32 PDT 2008
	    marcel at xserve.xcllnt.net:/nfs/freebsd/patch/smp/sys/powerpc/ 
compile/XSERVE-MP
	WARNING: WITNESS option enabled, expect reduced performance.
	cpu0: Motorola PowerPC 7455 revision 2.1, 1000.00 MHz
	cpu0: HID0 8450c0bc<EMCP,TBEN,NAP,DPM,ICE,DCE,SGE,BTIC,LRSTK,FOLD,BHT>
	real memory  = 526016512 (501 MB)
	avail memory = 508674048 (485 MB)
	FreeBSD/SMP: Multiprocessor System Detected: 2 CPUs

configuration:
	/usr/src over NFS using gem(4)
	/usr/obj local (PCI based ATA controller)

	gem0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu  
1500
		options=b<RXCSUM,TXCSUM,VLAN_MTU>
		ether 00:03:93:a8:cc:16
		inet 172.16.4.106 netmask 0xffffff00 broadcast 172.16.4.255
		media: Ethernet autoselect (1000baseT <full-duplex>)
		status: active

	atapci0: <Promise PDC20270 UDMA100 controller> port  
0x1090-0x1097,0x1080-0x1083,0x1070-0x1077,0x1060-0x1063,0x1050-0x105f  
mem 0x90030000-0x9003ffff irq 58 at device 21.0 on pci1
	atapci1: <Promise PDC20270 UDMA100 controller> port  
0x1040-0x1047,0x1030-0x1033,0x1020-0x1027,0x1010-0x1013,0x1000-0x100f  
mem 0x90010000-0x9001ffff irq 63 at device 27.0 on pci1

-- 
Marcel Moolenaar
xcllnt at mac.com