The range of prefixes used in the International System of Units (SI) has expanded to include new names covering very large and very small numbers, in part due to increasing data storage requirements in some sectors such as data science.
According to the UK’s National Physical Laboratory (NPL), these changes were recently approved at a meeting of measurement scientists and government officials from around the world at the 27th meeting of the General Conference on Weights and Measures (CGPM).
The move introduces two new prefixes at the high end of the SI range and two at the low end, which can now be used to express measurements worldwide, and is considered the first expansion of the SI prefix range since 1991. The proposal was led by Dr . Richard Brown, Head of Metrology at NPL.
These new names are Ronna (symbol R) for 1027 and quetta (symbol Q) for 1030while their counterparts at the other end of the scale are ronto (symbol r) for 10−27 and quecto (symbol q) for 10−30.
In the rather muddled language of the resolutions issued by the CGPM, she noted that “decisions were made at earlier meetings when it was considered timely to expand the range of SI prefixes”, and listed times when it had previously done so happened in 1960, 1964, 1975 and 1991.
The decision was made taking into account “the needs of data science in the near future to express amounts of digital information in the order of more than 1024” (which would be a yottabyte).
The resolution also highlighted the need to “avoid the importance of timely action to prevent unofficial prefix names from being de facto adopted”. Or in other words, the CGPM gets in early before anyone else decides to coin names for what would come after a yottabyte of storage.
According to the NPL, the change was largely driven by storage applications, which were already beginning to use prefixes at the top of the existing range (yottabytes and zettabytes) to express large amounts of digital information.
We look forward to hearing from storage providers who can promise us a quettabyte of capacity, although this may take a while as cloud storage provider BackBlaze detailed earlier this year that its platform is currently under a little over two exabytes of total data storage of his administration. that’s about two trillionths of a quettabyte. ®
https://www.theregister.com/2022/11/22/new_si_prefixes_clear_the/ New SI prefixes make way for quettabytes of storage • The register