BogoMips
BogoMips is a measure of CPU speed used in the Linux kernel . The value is determined during booting in order to adjust an internal waiting loop .
The name is derived from the English bogus - falsified, apparent - and the measure of (millions) instructions per second ([M] IPS). An often quoted definition is "the number of million repetitions per second that a processor is able to do absolutely nothing".
BogoMips is a value that is used to check whether the processor is within the usual performance specification compared to other processors of the same design. BogoMips determines the clock frequency of a processor as well as the potentially available CPU cache . It is not suitable for a performance comparison between different CPUs.
In 1993 Lars Wirzenius published an email in which he explained the need to introduce the BogoMips in the Linux kernel on comp.os.linux:
“MIPS is the abbreviation for Millions of Instructions per Second . It is a measure for the calculation of a processor. Like most of these measures, it is misused more often than properly because it is very difficult to correctly compare MIPS for different types of computers.
BogoMips are Linus Torvalds ' own invention. The Linux kernel version 0.99.11 (from July 11, 1993) needed a time loop that had to be adapted to the clock speed of the processor, but the time is too short and / or has to be too precise for inactive waiting. Therefore, when the kernel boots, it measures how fast a certain type of busy loop is running on a computer. “Bogo” comes from “bogus”, something that is a fake. With this BogoMips gives an indication of the processor speed, but it is far too unscientific to be called anything else than BogoMips.
There are two reasons why it is displayed during boot-up: a) because it is somewhat useful for debugging and checking that the computer cache or turbo button is working, and b) because Linus loves to giggle when he sees when people are confused about the messages displayed. "
The BogoMips can be calculated in advance using the following table.
The rating given is for the CPU with the then current and used Linux version. The index is the ratio of the “BogoMips per clock speed” for each CPU in comparison with an Intel 386DX CPU and is used for comparison.
| system | value | index |
|---|---|---|
| Intel 8088 | Measure × 0.004 | 0.02 |
| Intel / AMD 386SX | Measure × 0.14 | 0.8 |
| Intel / AMD 386DX | Measure × 0.18 | 1.0 (reference) |
| Motorola 68030 | Measure x 0.25 | 1.4 |
| Cyrix / IBM 486 | Measure × 0.34 | 1.8 |
| Intel Pentium | Measure × 0.40 | 2.2 |
| Intel 486 | Measure × 0.50 | 2.8 |
| AMD 5x86 | Measure × 0.50 | 2.8 |
| Mips R4000 / R4400 | Measure × 0.50 | 2.8 |
| Motorola 68040 | Measure × 0.67 | 3.7 |
| PowerPC 603 | Measure × 0.67 | 3.7 |
| Intel StrongARM | Measure × 0.66 | 3.7 |
| Nexgen Nx586 | Measure × 0.75 | 4.2 |
| PowerPC 601 | Measure × 0.84 | 4.7 |
| Alpha 21064 / 21064A | Measure × 0.99 | 5.5 |
| Alpha 21066 / 21066A | Measure × 0.99 | 5.5 |
| Alpha 21164 / 21164A | Measure × 0.99 | 5.5 |
| Intel Pentium Pro | Measure × 0.99 | 5.5 |
| Cyrix 5x86 / 6x86 | Measure × 1.00 | 5.6 |
| Intel Pentium II / III | Measure × 1.00 | 5.6 |
| AMD K7 / Athlon | Measure × 1.00 | 5.6 |
| Intel Celeron | Measure × 1.00 | 5.6 |
| Intel Itanium | Measure × 1.00 | 5.6 |
| Mips R4600 | Measure × 1.00 | 5.6 |
| Intel Itanium 2 | Measure × 1.49 | 8.3 |
| Alpha 21264 | Measure × 1.99 | 11.1 |
| Centaur VIA | Measure × 1.99 | 11.1 |
| Intel Pentium M | Measure × 1.99 | 11.1 |
| AMD Turion 64 MT | Measure × 1.99 | 11.1 |
| AMD K5 / K6 / K6-2 / K6-III | Measure × 2.00 | 11.1 |
| AMD Duron / Athlon XP | Measure × 2.00 | 11.1 |
| UltraSparc II | Measure × 2.00 | 11.1 |
| Pentium MMX | Measure × 2.00 | 11.1 |
| Pentium 4 | Measure × 2.00 | 11.1 |
| Centaur C6-2 | Measure × 2.00 | 11.1 |
| PowerPC 604 / 604e / 750 | Measure × 2.00 | 11.1 |
| Atmel AVR32 - AP7000 | Measure × 2.00 | 11.1 |
| Motorola 68060 | Measure × 2.01 | 11.2 |
| Intel Xeon (hyperthreading) | Measure × 3.97 | 22.1 |
| Hitachi SH-4 | Measure × 1 | No data |
| IBM S390 | Not enough data available yet | |
| POOR | Not enough data available yet | |
(Clock in MHz)
Individual evidence
- ^ Wim van Dorst: The Quintessential Linux Benchmark. linuxjournal.com, January 1, 1996, accessed August 28, 2012 .
- ↑ Eric S. Raymond , and Geoff Mackenzie , published on the Internet in the early 1990s, untraceable origin.
- ↑ Eric S. Raymond : Hackers Jargon File . Retrieved October 9, 2012.
- ↑ Wim Van Dorst: BogoMips mini-Howto . March 2, 2006. Retrieved November 24, 2012.
- ↑ Lars Wirzenius: printing & BogoMips . Retrieved October 9, 2012.
- ↑ Stas Bekman: What is a BogoMip? . Retrieved October 9, 2012.