the size of the former 2-gigabyte address space, or 18,446,744,073,709,600,000 bytes." 2008 The US National Institute of Standards and Technology guidelines require use of IEC prefixes KiB, MiB ... (and not kB, MB) for binary byte multiples p. 29, "The names and symbols for the prefixes corresponding to 210, 220, 230, 240, 250, and 260 are, respectively: kibi, Ki; mebi, Mi; gibi, Gi; tebi, Ti; pebi, Pi; and exbi, Ei. Thus, for example, one kibibyte is also written as 1 KiB = 2 10 B = 1024 B, where B denotes the unit byte. Although these prefixes are not part of the SI, they should be used in the field of information technology to avoid the non-standard usage of the SI prefixes." The binary prefixes are defined in IEC Standard IEC 80000-13, formally incorporating them into the ISO/IEC series of standards of quantities and units. IBM WebSphere describes data transfer using unambiguous IEC prefixes "The name of the file currently being transferred. The part of the individual file that has already been transferred is displayed in B, KiB, MiB, GiB, or TiB along with total size of the file in parentheses. The unit of measurement displayed depends on the size of the file. B is bytes per second. KiB/s is kibibytes per second, where 1 kibibyte equals 1024 bytes. MiB/s is mebibytes per second, where 1 mebibyte equals 1 048 576 bytes. GiB/s is gibibytes per second where 1 gibibyte equals 1 073 741 824 bytes. TiB/s is tebibytes per second where 1 tebibyte equals 1 099 511 627 776 bytes." "The rate the file is being transferred in KiB/s (kibibytes per second, where 1 kibibyte equals 1024 bytes.)" 2009 Apple Inc. uses the SI decimal definitions for capacity (e.g., 1 kilobyte = 1000 bytes) in the Mac OS X v10.6 operating system to conform with standards body recommendations and avoid conflict with hard drive manufacturers' specifications. Frank Löffler and co-workers report disk size and computer memory in tebibytes. "For the largest simulations using 2048 cores this sums up to about 650 GiB per complete checkpoint and about 6.4 TiB in total (for 10 checkpoints)." the SourceForge web site "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." The binary prefixes, as defined by IEC 80000-13, are