I was basically under impression that separating WAL is a big plus. On top of that, having separate partition to hold some other data - will do too. But it sounds - from what you said - like having all in single logical drive will work, because raid card will spread the load amongst number of drives. Am I understanding that correctly ?
both those models have merits.
doing a single raid 10 should fairly evenly distribute the IO workload given adequate concurrency, and suitable stripe size and alignment. there are scenarios where a hand tuned spindle layout can be more efficient, but there's also the possibility of getting write bound on any one of those 3 seperate raid1's, and having other disks sitting idle.
I'm trying to get an understanding of all options.
So out of 6 disks then having 4 in Raid 1+0 configuration and other two in mirror for WAL. That's another option then for me to test.