Extending the benefits of Professional Disc to IT users, the PDW-U4 is a portable, easy-to-use drive that can be used with a PC or Mac to view media files (using free Sony software). It also offers full read/write access with compatible non-linear editing systems. Succeeding the PDW-U1 and PDW-U2, the PDW-U4 supports four/three/two/single-layer XDCAM Professional Disc media. Used with four-layer media (write-once) it offers up to 128 GB capacity on a single disc. 4-channel dual DCHS drive technology approximately doubles system performance compared with the PDW-U2.