---my system---
[root@Arch ~]# hdparm -tT /dev/hda

/dev/hda:
 Timing cached reads:   508 MB in  2.01 seconds = 253.21 MB/sec
 Timing buffered disk reads:  106 MB in  3.03 seconds =  34.99 MB/sec

[root@Arch ~]# cat /proc/cpuinfo 
model name	: AMD Athlon(tm) XP 1600+
cpu MHz		: 1396.027
cache size	: 256 KB
bogomips	: 2811.95

---local and sync repos---
[root@Arch ~]# pacman -Q | wc -l
479
[root@Arch sync]# find -type d | wc -l
4139

---localdb desc && depends load---
[root@Arch ~]# sync; echo 3 > /proc/sys/vm/drop_caches 
[root@Arch ~]# time pacman -Qi > /dev/null

real	0m8.681s
user	0m0.124s
sys	0m0.145s

---sync desc && depends load---
[root@Arch ~]# sync; echo 3 > /proc/sys/vm/drop_caches 
[root@Arch ~]# time pacman -Si > /dev/null

real	0m4.639s
user	0m0.515s
sys	0m0.757s

---localdb files load + lstat for all files---
[root@Arch ~]# sync; echo 3 > /proc/sys/vm/drop_caches 
[root@Arch ~]# time pacman -Ql > /dev/null

real	0m57.057s
user	0m9.997s
sys	0m3.264s

---ldconfig---
[root@Arch ~]# sync; echo 3 > /proc/sys/vm/drop_caches 
[root@Arch ~]# time ldconfig

real	0m0.612s
user	0m0.027s
sys	0m0.038s

---install a ~4kb package---
[root@Arch ~]# sync; echo 3 > /proc/sys/vm/drop_caches 
[root@Arch ~]# time pacman -A xf86dgaproto-2.0.3-1-i686.pkg.tar.gz

real	0m8.408s
user	0m0.066s
sys	0m0.094s

---testdb (without Aaron's alpm_list speed-up) with empty disk cache---
[root@Arch ~]# sync; echo 3 > /proc/sys/vm/drop_caches
[root@Arch ~]# time testdb
wrong requiredby for esd : sdl_net
wrong requiredby for python-numeric : pycairo
wrong requiredby for xorg : xfce-utils
(grr, what's this?)
real	0m9.232s
user	0m0.789s
sys	0m0.063s

---repeat testdb (without Aaron's alpm_list speed-up)---
[root@Arch ~]# time testdb

real	0m0.814s
user	0m0.778s
sys	0m0.032s