Seagate Momentus 40GB HDD, 40 GB, 5400 RPM, 2 MB, 2.5", Ultra-ATA/100 Seagate Momentus 40GB HDD. HDD capacity: 40 GB, HDD speed: 5400 RPM, Storage drive buffer size: 2 MB, HDD size: 2.5", Interface: Ultra-ATA/100