What is the recommended setting for MAXDOP?

[Ahmad]

Hello everyone, I would like to ask you for help, or at least information, what is the recommended setting for maxdop? Thank you very much for informing me !!!

[Ciaran]

MAXDOP should not be 0 and should not be greater than half the number of visible schedulers.

For example if you have a quad core processor with hyper-threading enable, then you will have 4x2=8 visible schedulers (each scheduler is mapped to an individual processor).

Schedulers can be seen by running this query and would be the rows that have a scheduler_id < 255:

SELECT *
FROM sys.dm_os_schedulers
WHERE scheduler_id < 255;