Pentium II
From Free net encyclopedia
Image:Pentium II front.jpg The Pentium II is an x86 architecture microprocessor by Intel, introduced on May 7, 1997. It was based on a modifed version of the P6 core first used for the Pentium Pro, but with improved 16-bit performance and the addition of the MultiMedia eXtension (MMX) instructions which had already been introduced on the Pentium MMX.
The original Klamath Pentium II ran at 233 and 266 MHz, were produced in a 0.35 µm fabrication process and produced (for that time) an incredible amount of heat. They also worked with a 66 MHz front side bus, which was a speed that was inadequate for the CPU's design to show its full potential. A 300 MHz version was released later in 1997.
The Deschutes core Pentium II, which debuted at 333 MHz in January 1998, was produced in a more suitable 0.25 µm fabrication process and ran significantly cooler. Support for 100 MHz front side bus speeds heralded solid performance improvements. During 1998, Pentium IIs running at 266, 300, 350, 400, and 450 MHz were also released. Pentium II-based systems also saw the introduction of the new generation RAM-standard, SDRAM (which replaced EDO RAM), and the AGP graphics bus.
Image:Pentium II inside front.jpg Unlike previous Intel processors such as the Pentium and Pentium Pro, the Pentium II was packaged in a slot-based form-factor rather than a socket. The chip and associated components were carried on a daughterboard similar to a typical expansion board within a plastic cartridge. A fixed or removable heatsink was carried on one side, sometimes using its own fan. This larger package was a compromise allowing Intel to separate the secondary cache from the processor while still keeping it on a closely coupled bus. This separate cache was slower (running at half the processor speed) than that in the Pentium Pro, but the smallest cache size was upped to 512 KB from Pentium Pro's 256 KB. Off-package cache solved the Pentium Pro's low yields allowing Intel to introduce the Pentium II at a mainstream price level.
This arrangement also allowed Intel to easily vary the amount of L2 cache, thus making it possible to produce inexpensive but low performance and expensive but high performance versions of the CPU using the same core chip. Intel reverted to the more usual format of placing the processor on the mainboard with the Pentium III but continued the practice of selling essentially similar chips with small and large cache sizes, with the L2 cache moved onto the die itself.
The low-end version of the Pentium II - essentially a Pentium II with less (or none) level 2 cache - was marketed under the name "Celeron". It was not well received by many IT professionals due to substantially lesser performance compared with the more expensive product with L2 cache. However, the lack of the off-die L2 cache allowed for more fexibility with overclocking (the missing L2 cache was more sensitive to overclocking than the main chip). This overclockability led to heat issues, and the Pentium II celeron was one of the first chips for which aftermarket companies started to produce high performance cooling such as water-based or refrigerant cooling.
The Pentium II Xeon was a high-end version intended for use on servers. Principally, it used a different type of slot (Slot 2), case, board design and used expensive full-speed L2 cache, which was again off-die. Versions were produced with 512KB, 1MB or 2MB L2 caches by varying the number of 512KB chips incorporated on the board.
A mobile version with 256 KB of on-die, full speed cache was produced late in the chip's lifecycle, and was the fastest type of Pentium II. This design was seen in some Celeron based processors such as the 300A which became very popular with enthusiasts due to its low cost, overclocking friendly design and competitive performance.
By early 1999, the Pentium III superseded the Pentium II.
Contents |
Models
Klamath (350 nm)
- L1-Cache: 16 + 16 KB (Data + Instructions)
- L2-Cache: 512 KB, external chips on CPU module with 50% of CPU-speed
- Slot 1 (GTL+)
- MMX
- Front side bus: 66 MHz
- VCore: 2.8 V
- First release: May 7, 1997
- Clockrate: 233, 266, 300 MHz
Tonga (250nm), Pentium II Mobile
- L1-Cache: 16 + 16 KB (Data + Instructions)
- L2-Cache: 512 KB, external chips on CPU module with 50% of CPU-speed
- MMC-1, MMC-2, Mini-Cartridge (GTL+)
- MMX
- Front side bus: 66 MHz
- VCore: 1.6 V
- First release: ?
- Clockrate: 233, 266, 300 MHz
Deschutes (250 nm)
- L1-Cache: 16 + 16 KB (Data + Instructions)
- L2-Cache: 512 KB, external chips on CPU module with 50% of CPU-speed
- Slot 1 (GTL+)
- MMX
- Front side bus: 66, 100 MHz
- VCore: 2.0 V
- First release: January 26, 1998
- Clockrate: 266 - 450 MHz
- 66 MHz FSB : 266, 300, 333 MHz
- 100 MHz FSB: 350, 400, 450 MHz
Dixon (250nm), mobile Pentium II PE ("Performance Enhanced")
- L1-Cache: 16 + 16 KB (Data + Instructions)
- L2-Cache: 256 KB, on-die, full CPU speed
- BGA1, μPGA1 (GTL+)
- MMX
- Front side bus: 66 MHz
- VCore: 1.5, 1.55, 1.6 V
- First release: January 25, 1999
- Clockrate: 266 - 400 MHz
External links
- Intel press release introducing Pentium II
- Listing of various PII, PIII, and Celeron alphanumeric model designations
- Intel Pentium II technical specifications
- CPU-INFO: Intel Pentium II, indepth processor history
|
Intel processors 4004 | 4040 | 8008 | 8080 | 8085 | 8086 | 8088 | iAPX 432 | 80186 | 80188 | 80286 | 80386 | 80486 | i860 | i960 | Pentium | Pentium Pro | Pentium II | Celeron | Pentium III | XScale | Pentium 4 | Pentium M | Pentium D | Pentium Extreme Edition | Xeon | Core | Itanium | Itanium 2 (italics indicate non-x86 processors) |