Travelstar z5k500 is the second generation 7 mm 5400 rpm 25 inch hard drive from hitachi and the second generation advanced format drive advanced format increases the physical sector size on hdds from 512 bytes to 4 096 bytes which improves drive capacities and error correction capabilities the 500 gb per platter one disk models are designed as a direct replacement for standard 95 mm hdds for use in notebook pcs external storage and gaming consoles as well as the other thinner and mor