2010-02-26 11:17 AM
This is a great question and with everything in IT, it depends.
Typically, when you implement encryption using software you will notice a 30-50% performance degradation or greater in some cases but when implemented with specialized hardware devices, such as the DataFort encryption appliances and the Brocade Encryption Switch (BES), the performance impact is usually negligeable.
in the case of the BES, latency is in the order of 15-20 microseconds for disk encryption and in the order of 30-40 microseconds (with compression) for tape encryption. When these latency numbers are compared to millisecond I/Os for disk and tape, the latency becomes virtually negligeable and very little performance degradation will be observed either from the application user's perspective or the backup window size.