Players may experience slower or delayed download speeds, as Sony "manages" PSN traffic
You might want to make sure to pre-load games or get your downloads in as early as you can, on the PlayStation 4. Sony Interactive Entertainment announced that they would be working to ensure the stability of the PlayStation Network in Europe by carefully managing the heightened traffic due to recent country-wide lockdowns. According to Sony themselves, European PlayStation owners will have to deal with "somewhat slower" or "delayed" game download speeds from their servers. The statement was also posted to the North American Official PlayStation Blog, though it did not specify users in that region specifically. This follows other tech-related companies throttling or slowing speeds, to help deal with so many people using services like Netflix or YouTube, or after both Xbox Live and Nintendo Online services both suffered down-time.
UPDATE: If you are in the United States, as of March 26th, you will now be experiencing slower download speeds on PSN, as Sony is throttling traffic there as well.
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