. The X300 3.5” internal hard drive is designed for your professional or gaming PC – delivering reliable large capacity incredibly high-performance storage made possible by a number of advanced features including an ultra-high 512 MB 256 MB or 128 MB buffer. It even features improved positional accuracy for stable recording. The X300 is available in capacities of up to 16 TB – ideal for PC gamers graphic designers and other users with demanding storage requirements..