file_get_contents() with context to use http/1.1 significantly slow download speeds

Question

Using the code below each image download) file_get_contents() ) takes on average 8-15 seconds.....

If I do not use a context on file_get_contents() then image down

Answer 1

HTTP 1.1 requests are pipelined by default. If you don't "Connection: Close", it assumes "Connection: Keep-Alive", and then you have to wait for the connection to time out (since you never explicitly closed it) before the next loop will start.