Bests & Worsts Reviews from Amazon

I just built three new computers for a client's home use based on 9th generation i5-9400 and chose this wifi card as a cost-effective but high-speed connection. Win10 Home (1903) did not automatically install drivers so I downloaded and installed drivers from the FebSmart website, which installed without a hitch. However, the speedtest results on all three computers were extremely disappointing. After checking the properties of the connection, I found that it was connecting at only 2.4Ghz... which negates all of the advantages of AC speeds including MIMO and beam forming. Usually dropping down to 2.4GHZ is the result of a very weak signal (b/c 2.4GHz has a longer range than 5GHz), but the computers were only one to two rooms away on the same level. These are some steps I tried: • I thought maybe the computer case was blocking the signal, but turning the case so it was not between the antennas and wireless router made no difference. • I tried two different connections: first a TP-Link 1750AC router, then a high-end commercial grade Ubiquiti AC access point. Same results. • Finally I tried shutting down the 2.4GHz transmission on the router to force the wifi cards to connect at 5GHz, but the wifi cards could no longer even see the SSID — that provided me with the clue I needed... the cards were not operating at 5GHz at all! After poking around deep in the wifi driver properties... I finally found the problem — for some inexplicable reason, the driver's default setting was to run in 802.11b mode only (the slowest possible connection)... No wonder the speed was so abysmal! Additionally, your router could also be set to restrict wifi connections to specific modes which could result in unstable connections or even prevent connections altogether if this wifi card driver is restricted to modes not aligned with the router settings. The default mode I found might not be true for all installations or driver versions (this driver is 4.0.3.262), but if you run into an issue of extremely slow transfers or connectivity issues then checking the following might solve the problem: Device Manager / Network Adapter / Qualcomm Atheros QCA61x4 / Properties / Advanced / Wireless Mode: The mode choices range from 01 (11b) to 12 (11a/b/g/n/ac). Changing the mode from the default of 01 to 12 immediately resolved the problem. There are a few other modes which also support AC but restrict other connection speeds if you prefer. There is one other setting which could be significant: Preferred Band which defaults to 'No Preference' but can be changed to 'Prefer 5GHz'. After this crucial driver tweak, the connections are now blazing fast! I hope this helps anyone else experiencing unexpectedly slow transfer rates.