What this 8-position right-angle header is for
Its 3.00mm pitch sets the board footprint and the per-contact current ceiling — tin-plated contacts on a 3.00mm pitch typically carry 5 A per circuit, with the housing material limiting the temperature rise.
How it sits against the 1379030-3 sibling
The 644590-1 uses a 3.00mm pitch versus 2.54mm, which means a wider board footprint and higher per-contact current capacity. The 644590-1 also uses a latch holder for fastening, while 1379030-3 uses a friction lock — the latch holder provides a more positive mechanical lock under vibration. Both are active, both use tin-plated contacts, and both are through-hole right-angle. The choice between them is driven by position count and pitch: 8 positions at 3.00mm vs 12 at 2.54mm.