BTW, if your using the Ethernet ports on the 890 for LAN switching, and your hosts are directly connected to it, running their Ethernet interfaces at 100 Mbps, if they have gig capable NICs, then upgrading to a small gig standalone switch may very much improve transfer rate between hosts connected to it.
Also, if your hosts are all connected at 100 Mbps, 80% constant usage average would be in the ballpark for a host sending as quickly as it can to another, but unless you have more than one host sending to another host (all with ports of the same speed), you won't see drops in the router as the sending host cannot, physically, overrun the egress router interface.
In other words, the router isn't a bottleneck in the sense itself is not being adverse to data transfer rate between hosts.
Picture two hosts with a single 100 Mbps link between them. Insert a switch or router into that link, still using 100 Mbps, the switch or router, itself, doesn't cause any additional bottleneck beyond what the link alone provided. Yet, if you want to go "faster" than 100 Mbps, you would need "faster" host NICs and possibly "better" Ethernet cable (and if there was a switch or router in-line, when you upgrade the link wires to gig, it would be a bottleneck, itself, if it too can not support that rate). If the somewhat subtle distinction isn't clear, please let me know. But again, think of a wire without any switch or router in-line vs. one in-line, and then consider, is the in-line switch or router creating a bottleneck not already there from the wire alone.
