Brief overview: I am running Keil's HTTP Web Server on a board. The HTML page runs a JavaScript loop which fetches the file dynamic.cgx every 50 milliseconds.
When only a singular device is on the network, the file is delivered reliably every 50ms, the fetch taking 1-2ms on average. The moment another device connects, packet delivery slows down, waiting more than 500ms to respond to the fetch request.
On an iPhone, this issue does not occur. A bit of slowdown is seen, but not nearly to the level of the PC. This is not due to Safari, as the iPhone Google browser worked equally well.
WireShark with PC + Device (PC POV)
I can't packet sniff with a mobile device right now, so those aren't included