As you may read across the web the people are not that satisfied with Sony's PSN network: slow downloads, often down etc…
I had this slow downloads too, around 200 KBytes/s which is not acceptable when you are using the playstation store to buy games and need to download about 40 GBytes.
For me two simple tricks worked finally to push my line to max again:
- Set up a fast DNS provider like OpenDNS or Google's DNS servers. I chose OpenDNS because i am not a Google friend 😉
- Set the MTU setting of your LAN connection to 1473
I haven't tried the MTU setting with the wireless card because around the web a lot of people said that the wifi connection on the PS4 is crap. I used it at the beginning but had constantly voice chat dropouts so i gave it up.