Not knowing the details of your environment, I will assume that by "system" you are referring to a server of some sort. I will also make an assumption that since you mention a router, that there is thus some sort of network exists between your server and storage device.
The more items that sit between an application on a server and the storage device will contribute to overall latency. These items include software layers (file systems, volume managers and network and device drivers), network layers (protocols, interfaces, switches and routers, cabling, distance, bandwidth, effective latency) and the interfaces on the storage device. So, the fewer the layers, the less overhead and lower the latency should be.
Do you currently have a latency performance issue with the router or are you concerned about a potential challenge? If you are encountering performance problems, test the performance without the router and verify that the router and applicable networks are adequately configured and have the most current firmware and software.
This was first published in January 2006