The Extreme SSD uses a Sandforce controller and the SMART attribute for Lifetime writes is displayed in GB. The Ultra Plus uses a MArvell controller and if I remember correctly for Marvell The number listed 1015669923 is the total number of write operations issed by the host. Each write operation is done in 512bytes. To get the total GB written use the following method.
Number of total write operations x 512 = total number of bytes written
1015669923 x 512 = 520,023,000,576
Total number of bytes written / 1,024 = total number of kb written
520,023,000,576 / 1,024 = 507,834,961
Total number of kb written / 1,024 = total number of MB written
507,834,961 / 1,024 = 495,932
Total number of MB written / 1,024 = total number of GB written
495,932 / 1,024 = 484GB
