Without getting into the financials, I will say that the $/gflop wasn't bad. A Mac Pro rack was significantly cheaper per system than the next cheapest type of

Without getting into the financials, I will say that the $/gflop wasn't bad. A Mac Pro rack was significantly cheaper per system than the next cheapest type of rack we deployed (using Supermicro FatTwin systems, for a different use case). Server hardware is very expensive, and workstation or server class GPU hardware is not cheap either. Mac Pros are not the best price/performance ratio in that class, but they are (even now) within reason. Just because something photographs well, it doesn't mean that caution was thrown to the wind just to get something pretty. It's a datacenter after all, it's meant to facilitate a task. The rationale behind imgix deploying Mac Pros in a datacenter environment was pragmatic and based on certain fixed technical requirements.