EDIT: After a few months of running as below, it deteriorated. It will now run from a few minutes to a few hours before shutting down. I've tried different drivers, wattage controls, and other settings, but it's never worked reliably. Granted, AC1200 adapters are problematic. I have an AC450 adapter that has never dropped the connection. I have a third AC1200 adapter. Alpha was my second. My current adapter works better than the Alfa when it's at its best, but it's not as reliable as the AC450. The AC1200 is twice as fast as the 450. I think it's the Realtek chipset that the three adapters I tried have in common. Most manufacturers set up drivers, and most of the adapter's functionality resides in the software. I haven't seen any specific info on performance consistency between brands yet. Ratings appear to be based on factory performance. Installation was a disappointing experience. In a day and a half I installed and uninstalled it at least 4 times according to the manufacturer's instructions. Last time it worked for no apparent reason. The connection drops every now and then, but it can work without problems for a few days. Performance is within specification. I'm using it with an AC1900 router in a room where I don't have a wired connection. The speed is not gigabit but much better than 10/100. If it was more reliable I would be happier. I keep it. This comes close to solving my problem. I've tried other network cards in this speed range, but had less luck.
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