HP ProLiant DL288 ISS Technology Update, Volume 9 Number 1 - Page 3

ISS Technology Update Volume 9, Number 1 edition, Letter symbols to be used in electrical technology - Part 2: Telecommunications and electronics. Table 1-2 lists the names and symbols for the adopted binary prefixes. Pronounce the first two letters in each symbol like the corresponding SI unit followed by "bi" (short for binary, but pronounced "bee"). For example, one kibibyte (pronounced ki-bee-byte) is written as 1 KiB = 210 B = 1024 B. Table 1-2. Binary prefixes adopted by the IEC Factor 210 220 230 240 250 260 270 280 Value 1,024 1,048,576 1,073,741,824 1,099,511,627,776 1,125,899,906,842,624 1,152,921,504,606,846,976 1,180,591,620,717,411,303,424 1,208,925,819,614,629,174,706,176 Name kibi mebi gibi tebi pebi exbi zebi yobi Symbol Ki Mi Gi Ti Pi Ei Zi Yi Reprinted with permission of the IEC (see Legal Notices). Reducing the confusion To reduce confusion, vendors are pursuing one of two remedies: they are changing SI prefixes to the new binary prefixes, or they are recalculating the numbers as powers of ten. For disk and file capacities, the latter remedy is more popular because it is much easier to recognize that 300 GB is the same as 300,000 MB than to recognize that 279.4 GiB is the same as 286,102 MiB. For example, in 2009, the SourceForge web site reported file sizes using binary prefixes for several months before changing back to SI prefixes but switching the file sizes to powers of ten. For memory capacities, binary prefixes are more natural. For example, reporting a Smart Array controller cache size of 512 MiB is preferable to reporting it as 536.9 MB. HP is considering modifying its storage utilities to report disk capacity with correct decimal and binary values side-by-side (for example, "300 GB (279.4 GiB)"), and report cache sizes with binary prefixes ("1 GiB"). Let us know what you think. Provide your comments to the HP Reality Check: Server Insights blog at http://www.communities.hp.com/online/blogs/reality-checkserver-insights/default.aspx. Additional resources For additional information on the topics discussed in this article, visit the following sites: Resource SI prefixes IEC article : Prefixes for binary multiples Binary prefixes URL http://www.bipm.org/en/si/si_brochure/chapter3/prefixes.html http://www.iec.ch/zone/si/si_bytes.htm http://en.wikipedia.org/wiki/Binary_prefix 3