PowerTower & PowerCenter -- Power Computing announced two new lines of Mac clones last week, including a machine that qualifies as the fastest single-processor Mac available. The PowerTower line sports a PowerPC 604 processor running at a dizzying 166 or 180 MHz in a mini-tower case with three PCI slots, a minimum of 16 MB of RAM, and four drive bays. The PowerCenter line features a 120, 132, or 150 MHz PowerPC 604 in a low-profile (120 MHz) or desktop case, with three PCI slots and a minimum of 8 MB of RAM. Pricing for PowerTowers starts around $3,800, PowerCenters around $1,900. Tests so far show that the PowerTowers edge out Apple's high-end Power Mac 9500/150 by five to fifteen percent, even though they can't use memory interleaving, being based on the 7200 motherboard design (which is currently the only one that can crank a PowerPC 604 above 150 MHz). As with previous models, Power Computing machines ship with a keyboard, a significant software bundle (including Speed Doubler on the PowerTowers), and a 30-day, money-back guarantee. [GD]