Western Digital (WD) has shown its plans for changing the face of portable PC hard disk storage by formally announcing a family of 3-inch drives. The devices are expected to find favour particularly in the new generation of ultra-thin notebooks being made by IBM, Texas Instruments and others. The WD Portfolio connects to an EIDE bus and offers up to 70 per cent more platter capacity and better performance than the 2.5-inch drives that are the orthodox choice for mobile PCs, according to the firm. The drives are just 10.5mm high and offer an average seek time of 14ms. Data transfer rate conforms to PIO Mode 4 at 16.6Mb/sec. Drives are expected to be available in single-platter 1Gb capacity by the end of the year and in 1.4Gb form early in 1997, followed by two-platter 1.6Gb and 2.16Gb versions by the summer. WD claims that five of the top ten notebook makers will offer units with the drive, but declined to name OEMs.