Replace WD5000AAKS with WD5000AAKX?

I am running two wd5000aaks (s) in a Raid-1 configuration.  One of the drives has failed.  I have access to a wd5000aakx and would like to know if it can be mixed with the ‘aaks’ of if the replacement must be a ‘aaks’.

Thank you…

Hi, It is recommended to use the same model number, but if the have the same specs it should work. 

The AAKS is 3 Gb/s and the AAKX is 6 Gb/s, otherwise they are the same. 

Will the AAKX work ok?  Will it just default back to the slower speed of the AAKS?