IBM introduced the Gen. 10 of DS8K and I'm interested in the benefits of this new generation. With FCM4, DS8A00 is the first IBM enterprise storage system which offer hardwarecompression. Compression factors at tape backups are the base and then tests with ADRVCMPT FCM4 compression estimators followed. Hhome-grown processes had to bedeveloped for ADRVCMPT in order to perform practical analysis. As soon as the DS8A50 systems were added to production, we moved data to the new DS8A50 and the compression ratios were verified in reality. The changes to the configuration steps are also highlighted. In addition to the functional improvements, throughput was also measured. Better throughput results in better possibilities for logical corruption protection, whether with FlashCopy orSafeGuardedCopy.