But note that drive capacity has gone up too, often eliminating the need for many-disk arrays. For example, you can go up to 2TB on a single drive, so a simple RAID1 mirror may be all you need, and if you can arrange the mount points to match the use pattern you may get better performance out of several separate raid1 partitions where the heads can seek independently instead of essentially tying them all together in a
That is assuming a multi-platter disk and that you can actually partition things in such a way that different heads get to exclusively handle partitions most of the time.
single array. A many-disk array may do better on artificial benchmarks accessing one big file, but that's not what most computers actually do - and raid1 has the advantages of not slowing down when a member fails and you can recover the data from any single drive.
We are still talking about raid1+0 here...no raid5 or what not you know.