Arch Memory 256 GB SATA 3 III SSD Solid State Drive Certified for HP Pavilion Notebook g4-1015dx 1 x 256GB STD 2.5 Inch 7MM SATA3 Nand Flash: 3D V3 Sequential Read: Up to 540 MB/s Sequential Write: Up to 480 MB/s Random Read: Up to 70,000 IOPS Random White: Up to 90,000 IOPS Voltage: 5V  5% MTBF: 1,500,000 hours