TempDB default number of files in SQL Server 2016 Noticed the docs for SQL Server 2016 CTP2 state "by default, setup adds as many tempdb files as the CPU count or 8, whichever is lower."
https://msdn.microsoft.com/en-us/library/bb510411(v=sql.130).aspx

But I always thought that the "correct" ratio would be half the number of CPU cores, for boxes under 8 cores that is.

Should this be taken as the official recommandation from Microsoft and even applied to 2012/2014 ?
According to Paul Randal the number of tempdb files should be:


equal to the number of CPU cores for 8 or less cores
1/4 to 1/2 of CPU cores for more than 8 cores


I think it's a great news that Microsoft finally changed this default setting. The previous one was really bad - it caused problems with latch contention.

Paul Randal's article on the topic