Nik - good points. I used to run hardware projects at Apple and the EMC issues could definitely cause performance issues that influence other machines. But, Google could solve the EMC issues and not bother with certification. Another reason Google could be doing custom server hardware is they could create custom ASICs for various algorithms. their volumes are large enough and their algorithms mature enough that they could in theory create ASICs that are higher performing than running the algorithms in SW. There have been a variety of ASIC positions open at Google, and custom ASICs have been developed for network gear that Google also has manufactured. google's hardware team has server, network, and storage. I checked their job postings a year ago, and it looks like google is hiring more this year.

I don't think Google has bothered with EMC compliance in the past as their custom motherboards were not sold to others. Given it was for their own consumption, they could bypass the regulatory issues meant for those who sell IT equipment. Getting EMC compliance I would interpret means Google intends to sell Google labeled server HW. When you look at the way the Google motherboards have been installed in a rack, there is no nameplate that you would normally put a certification certificate.