Sony has confirmed that you will not be able to beef up your PlayStation 4's storage capacity with an external hard drive, as the console will not support such devices at this time.
In a Q&A on the PlayStation Blog, Sony revealed the news, saying flat out that "No, this feature is not supported on PS4." In addition, the company specified what kind of internal drives are supported, adding, "PS4 is equipped with a 5400 RPM SATA II hard drive. Users can choose to install a new hard drive so long as it complies with these standards, is no thicker than 9.5mm, and is larger than 160GB."
So there you have it. No external hard drives whatsoever. Might that change sometime down the line? Perhaps, but Sony didn't allude to there being such a possibility, so that's all we can go on for the time being. Is this going to be a major issue for you? Let us know in the comments below.