What are the "work-horse" machines at for example ILM like?

Like what kind of computers are used? I think back then at the time around Jurassic Park special workstations were used, SGI systems for example, right? But what about today? Specifically build machines? Off-the-shelf workstations? Studio-Macs?

Would be cool if someone could tell, cause I have kind of a bet going on... :b