what performance can i expect from a s905w 2/16gb?
I have latest nightly installed CoreELEC (official): nightly_20200223 (Amlogic.arm)
But i have poor wifi performance, only connected with 58mbit. 4K playback(if possible at all) not working.
Is there any way to improve that?
WIFI depends both on your router and your S905W Kodi device. I would suggest to buy an external USB WIFI dongle. Do some searching in CE’s forum to find recommended dongles. In addition, adjusting caching in Kodi could help you if the data transmission isn’t reliable (https://kodi.wiki/view/HOW-TO%3AModify_the_video_cache). Remember that S905W chipset doesn’t support HDR, so if you want to watch movies in 4K HDR, buy a new device (S905X etc…)
S905W was a budget SoC and more often than not was bundled with budget WiFi chipsets to save on manufacturing costs.
Some newer devices (mine included) can easily do 250mbit/30MB/s+.
Yes, buy a better box.
S905w is cheap but slow
Yes, s905w is cheap, slow, but still can playback high bitrate 4k with HDR and HD audio passthrough. It can do so reliably (with around 20-30% CPU usage) with CoreElec/Librelec), and unreliable with Android 7.1.2 (around 90% CPU usage, easy to get overheated) using the setup described below:
The ethernet port (100mbit) and wifi(2,4ghz) is too slow for reliable high bitrate 4k files, but you can use the usb 2.0 port to connect a usb HDD and connect it via a (cheap) usb 2.0 switch, where the other connection is to where you have the files stored.