What determines the LAN/SMB media file buffering speed for android devices Recently I started streaming media files through windows share and occasionally open them on my android devices(through solid file explorer LAN/SMB connection), I noticed for 1080p/2k videos, my LG G6 would open it rather instantly and I can browse videos without much buffering time. But for my Samsung galaxy tab it actually takes a few extra seconds to load the video and it has a noticeably longer buffering time if I jump around on the progress bar.

This got me curious, I wonder what caused the difference in buffering speed for my android devices. Is it the connection strength of the wifi signal, like my LG G6 would have a better wifi connection signal at home?

My router I'm using is NETGEAR Nighthawk X6S AC3000.
A number of factors may come into play here, firstly as highlighted by Morrison these devices may perhaps have different radio protocols (or standards) that they use and support different bands consequently different downlink speeds.

For more on this see: Why do two smartphones connected to the same WiFi network show different speeds (one displays the link speed as 135 Mbps and other only 72 Mbps)?

In addition, wi-fi signal and speed tend to degrade over distance and through obstacles like walls and this also affect the buffering time. Inteference is another factor, because so many devices predominantly one band use (the 2.4 GHz band), the resulting congestion can cause dropped connections and slower-than-expected speeds.

Having a number of devices connected to the router can significantly reduce speed and increase buffering time, so you may want to reduce the number of simultaneous connections while streaming.

Networking issues like IP address assignment (DHCP server) might be triggering the issue, constant drops in connection on a poorly configured DHCP server may be slowing connection speeds, you may need to try static IP address and observe the difference.

On the client-side media rendering capabilities of  the associated media players responsible for playback may also be a factor, you need to use a media player with latest codecs supporting given media formats and high resolution videos to allow a smooth playback.