Use 2nd ethernet port to improve network performance

[Lastmboy]

I'm trying to diagnose LAN performance issues. I have a 2009 Mac Pro acting as a file server and a 2013 Mac Pro as my desktop. There are gigabit switches between them with cat6 cabling. One of the switches feeds my TV and media box. I use the 2009 Mac Pro for all media downloading. My internet connection is 300 Mpbs. The problem is, whenever it is downloading anything, my LAN slows to a crawl. I am unable to watch any video from the server until the download completes. What I'm wondering is if the single ethernet connection to the server is my bottleneck. I saw someone mention that it will revert to 100 Mbps for the internet connection, so that I am not getting gigabit speeds everywhere else.

Forgive my ignorance, but is there a way to use the second ethernet port on the Mac Pro to improve network performance? i.e. could I use the one port for internet downloads and the other port for LAN access? Would I still be able to get internet access to the other devices on the network, along with gigabit speeds? I'm not sure how to configure it to test out this theory. Also, would upgrading my cabling to cat8 provide any benefit whatsoever?

Any suggestions appreciated.

 

[MacInWin]

Ethernet slows down from the max to the slowest device in the network. So you can have a gigabit switch and Cat6 cables and connect one old, slow device and the entire network will slow down to the slower speed. Adding more ports won't speed it up because the slowest device will still be in play. You can monitor network traffic in Activity Monitor, or with any third party network monitoring software you may want to use. Downloads, even over Ethernet, are real bandwidth hogs as the stream of inbound packets is very steady and very heavy. Ditto for streaming video from the server to your computer. So if you start a download AND a streaming session at the same time you are jamming a lot of traffic over the network, which will lead to a lot of collisions and a general slow down of the network, regardless of the speeds of the various devices. Adding another port into the same network won't help, as that port will just add to the already full pipeline.

So, what I suggest is that you review all of the devices in the network to make sure all of them are gigabit ready. And I would avoid downloads and streaming at the same time. Even if you are at gigabit speeds, that's a heavy load and likely to cause problems with traffic issues.

 

[chscag]

@Lastmboy:

Glad to see you back up and able to access our forums.