These take 4x Quadro FX6000, which is based on the GeForce 400 architecture. So, basically it's 4x GTX480. Which is crap for mining, really.
Basically, this.
The Quadro line is entirely workstation-oriented stuff. You get precision over speed, in short, but that's about all. In the case of mining, speed is about the only thing you want, and overspending ~5 fold on your power isn't the best idea.
These are about the most cost-ineffective cards available, as first nVidia's GPUs aren't nearly as cryptography-friendly as AMD's, AND these aren't the cheap, consumer-grade cards the provide the best price/performance in mining.