Through the use of technologies like 256-bit AES-GCM encryption, OpenSSL data transmission, LZ4 compression, speed and efficiency are at the core of Backup Pro's data integrity.
Both the Enterprise Server Edition (ESE) backup client and the Storage Platform use OpenSSL to encrypt and decrypt data using 256-bit AES-GCM. OpenSSL is optimised to be extremely fast, and both encryption and decryption are super fast. (We have found speeds of +- 1.5 GB/s on an Intel i7 with 32GB RAM). 
For a more elaborate explanation, see the overview of Backup Pro's Data Integrity.
Performance is further improved by using the LZ4 compression algorithm, which provides good compression but is especially impressive with decompression speeds. 
Both MD5 and SHA256 are used to calculate file thumbprints. The combined approach is effectively as fast as MD5 on its own. (Again, we have found speeds of about 600 MB/s on an Intel i7 with 32GB RAM).
The above processes only keep a single CPU core busy per disk being processed. The ESE backup client is therefore only limited by the disk and network speeds.
For additional information about disk usage, see Backup Pro ESE: Technical Overview.
In addition, a 16MB buffer is used for network data transmission while any of the above occurs. This balances out the latency caused by opening files.
A note regarding performance degradation: The time needed to open a file is most evident when there are many small files. If the disk and network are fast but you're not getting the expected throughput, performance degradation could be due to the Storage Platform being busy with other tasks or serving other backup clients.
"On Intel Core i3/i5/i7 and AMD APU and FX CPUs supporting AES-NI instruction set extensions, throughput can be over 700 MB/s per thread."
|LZ4 fast 17 (r129)||1.607||690MB/s||2220MB/s|