Powers of two are often used to measure computer memory. A byte is now considered eight bits (an octet, resulting in the possibility of 256 values (28). (The term "byte" once meant (and in some cases, still means) a collection of bits, typically of 5 to 32 bits, rather than only an 8-bit unit.) The prefix "kilo", in conjunction with "byte", may be, and has traditionally been, used, to mean 1,024 (210). However, in general, the term "kilo" has been used in the International System of Units to mean 1,000 (103). Binary prefixes have been standardized, such as "kibi" (Ki) meaning 1,024. Nearly all processor registers have sizes that are powers of two, 32 or 64 being very common.