Hardware Compression vs. Software Compression

Software compression is more well-known among people when compared with hardware compression. The reason is that the majority of people do not have need to apply hardware compression in their daily life. In contrast, software compression does meet their requirements in many aspects. Generally speaking, software compression is cheaper and more easily accessible solution compared with hardware compression. On the other hand, hardware compression demands specialized equipment which is designed to deal with specific workload. Even though hardware compression costs users more, it does have its own advantages over software compression. First of all, the specialized hardware enables hardware compression to be faster than software compression to a great degree. Software compression just requires a general purpose processor in order to perform its job. Secondly, hardware compression will not cause any extra burden to the host processor because its calculations take place within its own hardware. Software compression cannot make it. Under most circumstances, software compression is likely to degrade the performance of the host during heavy use and other operations. If you are compressing a large amount of data while using your computer at the same time, then this may pose a great threat.

There is no doubt that software compression has advantages as well. First, it costs less. Second, software compression offers users a lot of options to choose from. Users are allowed to control the process of how the data is archived, compressed and formatted. In comparison, users are given very few, or no options at all with hardware compression. Users have no say in the process of how the data is compressed before being stored into the media. Everything has been pre-programmed into the hardware by the manufacturer.

In conclusion, software compression is better if you are going to store compressed data for a long time. Hardware compression is usually device specific, which may cause great problems when your device fails without anything can replace it.

Hardware Compression

Generally speaking, the hardware compression is performed on the data path level. As a matter of fact, the hardware compression is only available for the data path which directs data to tape libraries. Under this circumstance, the uncompressed data will be sent from the client computer to the media through the data path. Therefore, the data will be compressed by the tape drive hardware before being written to the media.

There is no doubt that hardware compression is faster than software compression most of the time. The reason is that hardware compression is operated by dedicated circuitry. As a result, the hardware compression is ideal for direct-connect configurations in particular where the subclient and MediaAgent are hosted by the same physical computer. In such configurations, the drives are able to compress the data at the same rate as it is sent by the subclient as there are no network bottlenecks throttling the data transmission to the media drives. On the other hand, the hardware compression can boost the virtual capacity of the tape but also the performance of the data protection thanks to the tape storing more data per unit with higher operation speed. 

However, the problem is that hardware compression is not supported by disk library. It is only applicable for tape libraries.

If the data secured by data protection operations must compete with other data for network bandwidth, then hardware compression may be not that useful. When the network is congested, the tape drives will be starved for data for the data cannot be supplied quickly enough. Under such circumstance, the drives can compress as well, but the drives are likely to stop and restart the media in order to wait for more available data. Therefore, the compression performance may not be very ideal, which may lead to some potential problems.