Suppose my cable internet speed is 100mbps. What is the highest speed I should expect on my wifi? obviously this depends on protocol, band and etc. I am interested in knowing the maximum possible speed I can expect on 2.4GHz and 5GHz networks, so I have reference point for troubleshooting and performance tweaking.

More to the point: I have TP-link EAP225 Access point. internet cable speed running to it is 70mbps. speed I am getting on 2.4GHz band is 20mbps, 5GHz is 40-50mbps. Are these good results or am I rightfully upset? What speeds should I be expecting?

  • What speeds you can expect can be reliably calculated with the right information. You need to tell us what your client Wi-Fi hardware is and we can look up what speed-related Wi-Fi features it supports and how that relates to your AP's speed-related Wi-Fi features. The overlap of what they can do, minus typical 30% overhead, determines the top speed you can get under excellent radio conditions. – Spiff Apr 7 '20 at 15:59
  • One tip: Someone told me a week or so ago that he got a TP-Link AP that defaulted out of the box to 20MHz-wide channels in 5GHz, instead of the 80MHz-wide channels it is capable of. Channel width is directly proportional to performance (all else being equal) so using just one-quarter of your channel width capabilities means getting just one-quarter of your performance potential. Make sure your EAP225 is set for 80MHz-wide channels on 5GHz. – Spiff Apr 7 '20 at 17:04

Under ideal conditions, that is, AP serving only a single WiFi client within about ten meters with a clear line of sight, and no neighboring APs nor WiFi devices causing channel interference, your speed will be limited by the performance of either the AP or your WiFi client. The speeds you quote are typical for 2.4 and 5GHz bands. Most WiFi clients will not exceed 70Mbps, but if you care to eliminate Internet and ISP from your tests you can setup a speedtest host on your LAN. Under Linux, there is the iperf3 package (both client and server). I expect it would also work under WSL (Windows Subsystem for Linux).

  • they actually have binaries for windows. Ill test it soon – GKman Apr 7 '20 at 12:36
  • Those don't sound like "ideal conditions" speeds at all – here I'm getting over 100 Mbps with 802.11n on the 2.4 GHz band (admittedly that's with a 40 MHz channel...) And on 5 GHz you have 802.11ac, and greater channel widths on top of that, so if both devices are ac-capable it should go well into hundreds of Mbps. – user1686 Apr 7 '20 at 13:16
  • 1
    Thanks user1686. I stand corrected. I do have point to point AC links with upwards of 350Mbps. By 'typical' I meant, what I see on most networks w/o optimizing for throughput. I could have more clear. Thank you. – Shawn Hughes Apr 7 '20 at 13:35

[The question in your body text is a bit different than the question in your title. Below, I've answered the question in your body text.]

Short answer: Under excellent radio (signal/noise) conditions and decent but realistic client hardware, you should expect to see 600Mbps on 5GHz, and 100Mbps on 2.4GHz, from a device with the Wi-Fi radio capabilities the EAP225 seems to have.

Long answer: Your EAP225 appears to support the an 867Mbps 802.11ac PHY rate by using 80MHz-wide channels, 2 spatial streams, MCS 9 (QAM-256) on 5GHz. With typical overhead, under excellent signal and noise conditions, a client capable of all those same Wi-Fi speed-increasing mechanisms should see TCP over IPv4 throughput as high as 600Mbps when talking to a device connected to a gigabit Ethernet LAN port of the EAP225. Please note that signal drops of dramatically as you move away form the AP, which means that PHY rates drop off dramatically as well. Also, noise on the channel, including other devices using the same AP, and other APs nearby using the same channel, will lower the expected throughput as well.

On the 2.4GHz band, your EAP225 appears to support the 450Mbps 802.11n PHY rate by using 40MHz-wide channels, 3 spatial streams, and MCS 15. However, most client devices only support 2 spatial streams, and anything that uses Bluetooth will ask the network to only use 20MHz-wide channels in order to leave room for Bluetooth, so those two vary common situation knock your expected PHY rate down to 144 Mbps, for an expected TCP over IPv4 throughput of 100 Mbps, again, under excellent RF conditions, and when talking to something on a gigabit Ethernet LAN port of the EAP225.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.