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Welcome!Well the specs are:
Wi-Fi Data Rate
• 2.4 GHz Band: up to 800 Mbps
• 5 GHz Band: up to 1,733 Mbps
To take full advantage of this you would need a wireless device to connect at 1300 or 1733mb to get full connection rates on 5Ghz and I presume with compressed 4K, smooth video might be achieved. 1080p should be smooth as well...
I don't have 4K support for anything at the moment. I know that raw 4K is very bandwidth intensive and not sure if any router can handle raw 4K. Raw 4K runs in the 10Gb bandwidth range and to even steam it smoothly, you would probably need a 10Gb LAN wired supporting network system.
I tested 1080p raw BD files years ago with DIR series AC calls routers and bridges. Even with the best configuration and settings and connection rates at 1300Mb, my boxee box would buffer occasionally with it's 100Mb LAN port connected to a 1300Mb wireless bridge. The higher bandwidth the raw BD file was, the worse the buffering was. I presume that there was some bandwidth issues in processing the raw data from AP to bridge and to the boxee. When I connected by boxee box to wired Gb switch, I get zero buffering of raw 1080p BD files. So after all that I kept the boxee hard wired always. Wireless can't compete with Gb LAN connections.
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Given that, I presume that maybe the COVR system will work, however I don't know for sure. Kind of depends on your source video data and device support on how they process the 4K data and such.
The COVR is supposed to have MIMO which maybe beneficial as well to streaming. I guess also client devices need to really support MIMO as well to take full advantage of it.
Only thing I would suggest is to find a local shop that has them or Amazon which have a good refund policy and test it out. If it's not working as you feel, then you can return it.
The 895L is about 1.5 years old, kind new and FW is still under development. I believe that has 3 radios like the 890L does.
Wi-Fi speeds of up to 5332Mpbs (1000Mbps + 2166Mbps + 2166Mbps)
The DIR-89x series was supposed to support MIMO however I believe there were problems in the wifi chip set.