Ethernet Shield: Maximum speed Looking at this shield here: https://store.arduino.cc/arduino-ethernet-shield-2

It states that "Connection speed: 10/100Mb". However from looking at various forums it appears that no one can get much more than 300Kb/sec with this device?

Can anyone explain what causes this limitation and how to overcome it? If its SPI that is the bottleneck is there some alternative? I am looking to get speeds of 6 mega bytes per second or more using a TCP connection.

I am extremely new to all this so apologies if I've missed something extremely obvious here. I also had a look at bluetooth/wifi shields but it appears they seem to also have some similar throughput issues. USB looked like it could work but is extremely complex for a newbie.
It's not just the SPI what limits overall speed. You also need some proccessing power, and AVR based Arduinos lacks of it. It all depens what do you want to do with data.

If you need some serious processing power, it might be better to use something much more powerfull, like raspberry PI with real operating system. You can even run some web server at the speeds you can't even imagine with Arduino with the ethernet shield