SataPortMap这个值应该怎么设置

这段话我始终看不懂，像我的机器有3个sata槽，2个3.0；1个2.0。那么SataPortMap=？

##########################################################################################
### If having trouble with sata, specify how many ports you have
### put disks on port 1,2,3,4 and put SataPortMap=4
### SataPortMap=4 means first 4 ports of 1st controler.
### SataPortMap=44 means first 4 ports of 1st controler and first 4 ports of 2nd controler.
### SataPortMap=422 means first 4 ports of 1st controler,
### first 2 ports of 2nd controler and first 2 ports of 3rd controler.
##########################################################################################
set sataportmap="SataPortMap=242"