The following graph shows the overall performance of the NAS on all tests we conducted using our custom made software.
Apparently the Marvell CPU is the bottleneck at RAID 6 and RAID 5 tests so the NAS shows higher transfer speeds with a single disk configuration. Also the USB 2.0 interface is clearly a bottleneck for the external storage speed tests. It is a shame that the TS-419P II does not feature USB 3.0 ports.
Now let's check the performance of the TS-419P II against other NAS devices. Currently we have measurements of only one NAS (excluding the review's test sample) but after more reviews the following graphs will become much richer.