BogoMips
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BogoMips (from "bogus" and MIPS) are an unscientific measurement of CPU speed made by the Linux kernel when it boots, to calibrate an internal busy-loop. An oft-quoted definition of the term is "the number of million times per second a processor can do absolutely nothing".
As a very approximate guide, the BogoMips can be pre-calculated by the following details:
SYSTEM RATIO INDEX Intel 8088 clock * 0.004 0.02 Intel/AMD 386SX clock * 0.14 0.8 Intel/AMD 386DX clock * 0.18 1 (definition) Motorola 68030 clock * 0.25 1.4 Cyrix/IBM 486 clock * 0.34 1.8 Intel Pentium clock * 0.40 2.2 Intel 486 clock * 0.50 2.8 AMD 5x86 clock * 0.50 2.8 Mips R4000/R4400 clock * 0.50 2.8
Motorola 68040 clock * 0.67 3.7 PowerPC 603 clock * 0.67 3.7 Intel StrongArm clock * 0.66 3.7 Nexgen Nx586 clock * 0.75 4.2 PowerPC 601 clock * 0.84 4.7
Alpha 21064/21064A clock * 0.99 5.5 Alpha 21066/21066A clock * 0.99 5.5 Alpha 21164/21164A clock * 0.99 5.5 Intel Pentium Pro clock * 0.99 5.5 Cyrix 5x86/6x86 clock * 1.00 5.6 Intel Pentium II/III clock * 1.00 5.6 AMD K7/Athlon clock * 1.00 5.6 Intel Celeron clock * 1.00 5.6 Intel Itanium clock * 1.00 5.6 Mips R4600 clock * 1.00 5.6
Intel Itanium 2 clock * 1.49 8.3 Alpha 21264 clock * 1.99 11.1 Centaur VIA clock * 1.99 11.1 AMD K5/K6/K6-2/K6-III clock * 2.00 11.1 AMD Duron/Athlon XP clock * 2.00 11.1 UltraSparc II clock * 2.00 11.1 Pentium MMX clock * 2.00 11.1 Pentium 4 clock * 2.00 11.1 Centaur C6-2 clock * 2.00 11.1 PowerPC 604/604e/750 clock * 2.00 11.1 Motorola 68060 clock * 2.01 11.2 Intel Xeon (hyperthreading) clock * 3.97 22.1
Hitachi SH-4 clock * 1 IBM S390 not enough data (yet) Intel ARM not enough data (yet)
The ratio is the typical ratio for that CPU with the then current Linux version. Since some caching aspects have been changed for some CPUs (notably the Intel ones) in the development of the kernel, other ratios may be applicable to those CPUs as well. Full and complete information and details about BogoMips, and hundreds of reference entries can be found in the BogoMips mini-Howto (see below).
External links
- BogoMips Mini-Howto (http://www.clifton.nl/index.html?bogomips.html)
- The Jargon File: BogoMIPS (http://www.catb.org/~esr/jargon/html/B/BogoMIPS.html)
- This article was originally based on material from the Free On-line Dictionary of Computing, which is licensed under the GFDL.