Two duallies on this desktop:
An Asus P2B-D @ 133FSB running 600 Coppermine E's @ 800 (hardmodded to EB and 1.85v) w/ 512MB PC133 CAS2 RAM, and a Tyan Titan Pro 1668S running a pair of 180 PPros @ 233 w/ 256MB EDO RAM (an oldie but a goodie!).
Dual 21" monitors @ 1600x1200 on the Asus box, with one of 'em shared by the PPro via a button on the monitor (dual inputs).
Oh, they're both pure-SCSI architecture -- it makes that legendary SMP smoothness all the more creamy...