Photo of the racks in the original Google datacenter
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Here's a closeup of a nic on one of the machines: http://friendfeed.com/e/e7bc8124-ee7f-4949-91d2-773e410613d3... I took this picture two months ago at the Computer History Museum, where the jj rack is on display.
My understanding is that they found the HP ProCurve switches were a better deal to buy two chassis and stuff all the blades into one box rather than buy the blades and add them to one. It was cheaper that way.
Fans?
BTW, here's a video (taken by someone else): http://www.youtube.com/watch?v=z19-6tvGSq4
http://www.acm.uiuc.edu/conference/2007/speakers http://www.acm.uiuc.edu/conference/2008/
I remember seeing videos of Yegge's and Munroe's talks. Yegge's is worth watching.