The Xbox Series X is truly a next generation console offering enhanced performance across the board. Games load in a fraction of the time and download speeds have increased significantly. Although the Xbox Series X has built in WiFi if you want to truly get the fastest download speed you will want to use a wired connection.
The ethernet port on the Xbox Series X and Xbox Series S is a standard gigabit ethernet port capable of supporting speeds of 1 Gbps. This is the same as the previous generation Xbox One X and not truly next generation, with standards of 2.5 Gbps and 10 Gbps emerging into the consumer market. That said, the gigabit ethernet interface is fast enough to take full advantage of most internet connections including gigabit offerings from Xfinity, Spectrum, and Verizon.
To take full advantage you will need a router that has gigabit ethernet ports, a proper ethernet cable, and a suitably fast internet connection. The speed test utility on the Xbox Series X and Xbox Series S shows that speeds of 945+ Mbps are easily obtainable. Running speedtest.net from the integrated Microsoft Edge browser yields a very similar result confirming the accuracy of the test.
Unfortunately downloads from Xbox Live appear to currently max out at about 300 Mbps. This is the result of server side throttling, a very common technique used by most online services. 300 Mbps is still a very good download speed but disappointing to anyone who has a 500+ Mbps internet connection. At 300 Mbps a 20 gigabyte game download takes just under 9 minutes. That is fast for sure but still slow when you consider that at true gigabit speeds that same download would take a mere 2 minutes 45 seconds.
Given that the average broadband speed of 135 Mbps according to speedtest.net this is likely not an issue for most people who are still severely limited by their internet connection. At 135 Mbps that same 20 gigabyte file would take 19 minutes 45 seconds. That is still not a terrible result. Overall download speeds on the Xbox Series X and Xbox Series S consoles are much faster than with previous generations of Xbox consoles.
If your internet speed is much lower don’t despair. The recommended download speed for Xbox Live is only 5 Mbps and anything 3.5 Mbps or higher is supported. Despite popular belief online gaming is not that bandwidth intensive. Latency is king when it comes to online gaming. If your latency is high you will experience lag when playing games online. No amount of download speed will fix your latency. Latency and bandwidth are completely different metrics. You do not need a lot of bandwidth to use Xbox Live. Of course downloads will take much longer. That same 20 gigabyte download on a 5 Mbps internet connection would take over 8 hours 45 minutes.
Overall the gigabit ethernet port on the Xbox Series X and Xbox Series S is more than sufficient to deliver next generation speeds but is not cutting edge by todays standards, Similarly the lack of Wi-Fi 6 is a disappointment but not a deal breaker by any means, If you want to get the best performance out of your Xbox Series X or Xbox Series S console using a wired ethernet connection is going to be your best bet, even if your internet speed is low using ethernet will reduce your latency greatly. Latency is king for online gaming.