Please read carefully. Thank you!!! About SSD: SSD doesn't inclube SSD holder, SATA cable and screws. 120G is 850 evo ,250G-1T is 860 EVO !! Storage Space: 250GB = approximately 200GB-240GB 500GB = approximately 440GB-490GB 1TB = approximately 880GB-980GB Market Conversion 1GB=1.00 Billion Bytes, Computer Conversion 1GB=1.073741824 Billion Bytes. (Note: The market conversion for GB to Bytes slightly varies. Google "Memory Card Capacity" for more information.) 860 EVO Specifications Capacity: 250G 500G 1TB(*Actual usable capacity may be less,due to formatting, partitioning, operating system, applications or otherwise) Interface: 2.5', SATA3 6Gb/s(compatible with SATA2 , SATA1,to drop speed ) Controller: SAMSUNG MJX Performances Speed (different test softwares will get different speed , speed will be affected by many different factors , our datas only as reference) 250G 500G 1TB Speed (ATTO): Sequential Read Speed: Up to 550MB/s; Sequential Write Speed:Up to 520 MB/s. Notice: 1, The test result is base on sataIII interface,sataIII sata cable,desktop and SSD empty status , different computer and software (include software version), the result may different . 2, Difference between SATA I, SATA II and SATA III SATA I (revision 1.x) interface, formally known as SATA 1.5Gb/s , is the first generation SATA interface running at 1.5 Gb/s. Max speed 150MB/s. SATA II (revision 2.x) interface, formally known as SATA 3Gb/s, is a second generation SATA interface running at 3.0 Gb/s. Max speed 250MB/s. SATA III (revision 3.x) interface, formally known as SATA 6Gb/s, is a third generation SATA interface running at 6.0Gb/s. Max speed 550MB/s. This interface is backwards compatible with SATA 3 Gb/s interface. If sata3.0 SSD tested speed on sata2.0 interface and sata cable the result will be inaccurate. 3,According to the international stander 1000KB=1MB ,the real capacity =Capacity x 0.93, please notice that . Before you use it please right click "My computer-Management-Device manager-disc drive" and can find our SSD. Please do the format and partition . Warranty 860 250GB: 5 years or 150 TBW limited warranty 860 500GB: 5 years or 300 TBW limited warranty 860 1TB: 5 years or 600 TBW limited warranty Tip: The images, models, data, functions, performance and rules parameters of this page are only for reference. Samsung may make improvements to the above contents. For more information, please refer to the product information, product description or Samsung official website. Unless other stated, the data on this page are the internal nuts tested by Samsung, the comparison involved is compared with Samsung products