HARDWARE 1 course of YBET Informatique

Chipset pour ordinateur PC
YBET informatique Hardware training YBET CONTACT

8. The chipset

8.1. Introduction - 8.2. Structure Pentium 8.3. Structure Pentium II 233 - 450 MHz, first Pentium Pro - first Pentium III 450 to 600 MHz - 8.4. Camino INTEL i820 - 8.5. INTEL i810 - 8.6. ALI chipset Aladdin TNT2 - 8.7. VIA Apollo Pro 133 and Apollo VCM133 - 8.8. VIA Apollo KX133 and KT 133 - INTEL i815/815E - 8.9. VIA ProSavage PM133 - 8.10. INTEL i840 - 8.11. INTEL i820E - 8.12. INTEL i850 - 8.13. AMD-760 - 8.14. NVIDIA for Athlon and Duron - 8.15. INTEL i845 - 8.16. INTEL i865 and i875 - 8.17. In conclusion

8.1. Introduction

The processors speed evolution is limited by external parts: the peripherals, memories, specifications of the bus are far from reaching speeds of the processors. The processors manufacturers thus stuck much to the external circuit of management of interface processor - peripherals: the CHIPSET. If a motherboard 8088 comprised a hundred electronic circuits, the number is reduced by Chipset which take again the whole of the internal connections (bus, hard disks) and external peripherals (USB, series, parallel...). The chipset is used as interface between the processors and its peripherals (memory, inputs/outputs). It is the essential component of a motherboard.

The chipset generally does not consist of only one circuit, but of 8 for oldest and 2 in the modern circuits (Northbridge and Southbridge).

Approximately, Northbridge is used as bond between the processor and the memory, while southbridge manages inputs/outputs (PCI port and AGP...).

For newer processors (I7, I5 or Ax series), northbridge is directly integrated in processor: PCI-E controller for Intel, memory controller for both AMD and Intel, but also, graphic GPU.

For the complete list of the chipset

8.2. Structure Pentium

Here the motherboard structure for processor PENTIUM, PENTIUM MMX, K5 and K5 MMX (not K6-2 or K6-3). Bus ISA is derived from PCI bus.

According to the processor speed, external speed (FSB) can be different. One finds on the motherboards speeds of 50, 60, 66 and 75 MHz. The more important external speed is, the more the total speed of the PC is fast. The starting characteristics are given by the supplier of the processor, "overclocking" external speed can bring some problems. For Pentium INTEL, external speed, called FSB for Front Side Bus, is of 66 MHz maximum! Simm are limited at this speed.

The CHIPSET used for these processors are series INTEL 430, followed of 2 letters.

It will be necessary to be wary of the motherboards containing chipset FX and HX. These boards received a memory hiding place external 256k or 512K of the insertion type. Even if the circuits are equivalent from their form, the masks are not compatible between-them. In the event of instability on these boards, decontaminate the external mask on the level of Bios.

8.3. Structure PENTIUM II 233 - 450 MHz, Pentium III up to 600 MHz, Pentium Pro

8.3.1. 440 LX: Pentium II 233 -333 MHz and Pentium Pro

  The CHIPSET used for the first processors Pentium and Pentium Pro are series INTEL 440, followed of 2 letters.

The architecture of the CELERON is identical, except the memory cache. Let us note that the 440EX is an attached version of the 440 LX intended for the CELERON

8.3.2. Structure Pentium II from 350 - Pentium III 450 to 600 MHz

The great evolution here comes from .INTEL 440 BX chipset This circuit of interface manages the Front Side Bus left to 100 MHz. Notice that you can always use a 440 BX card for of Pentium II inferiors or the CELERON (attention to new the socket 370 for the CELERON).

440 ZX are practically identical to the 440 BX. It manages only 2 dimm

8.3.3. Pentium Pro

First Pentium Pro (FSB 66) used sets of equivalent components

440 FX equivalent to the 430 HX, brings the management of memory ECC, i.e. the car-corrective memory. This chipset was also used on the first motherboards integrating Pentium II.

450 KX and the 450 GX (chipsets specific Pentium Pro) have them, brought a particular management of bus PCI. The 450 GX makes it possible to manage 2 buses PCI and 2 Buses report, for each couple of processor. Moreover it makes it possible to manage a EISA bus (processors 486), mainly to preserve a compatibility with the old waiters, but without real technical interest.

8.4. Camino INTEL I820

Left at the end of 1999, Camino makes it possible the data bus of the processor to function at an external frequency of 133 MHz (Front Side Bus), for 100 MHz for the 440 BX. This brings a profit of 33 % of performances. It is used with processors INTEL Pentium III of the series B (533B and 600B). The i820 manages Direct Rambus (also called DRDRam), a new type of read-write memory which turns to 300 or 400 MHz, more expensive than the PC100 Dimm. The INTEL 820 is not designed to manage SDRam. INTEL markets in option for the motherboards containing i820 Memory Translator Hub (or MTH) which makes it possible to manage SDRam PC 1OO. One of the principal interests of DRDRam resides in its flow sufficient for the AGP 4X, one of the innovations of the INTEL 820. The AGP 4X offers a band-width higher than 1 GB/s - against 528 MB/s for the AGP 2X. This is important only for the plays and applications 3d. The chipset i820 makes other improvements, as the architecture accelerated I-Iub which provide direct connections to a flow of 266 MB/s (133 MB/s for the 440BX) between the chipset and the subsystems controllers IDE, USB and PCI. At the same time, the interface Ultra DMA/66 doubles the flow in gust mode of the hard disks: 66 MB/s against 33 MB/s for the Ultra DMA/33.

The INTEL 820 supports the biprocessor treatment in symmetrical mode SMP (symmetry multiprocessing). In the last, the i820 has a generator of random random numbers which, according to INTEL, improves the operations of encoding, safety and authentification.

FSB 100 MHz, Memory PC 100 SDRam, AGP 2X, UDMA 33 FSB To 133 MHz, Memory Rambus DRDRam, UDMA 66, AGP 4X.

The bridge towards an ISA bus is optional

8.5. Chipset INTEL I810

Left at the end of 1999, this circuit incorporates some specificities of I820 like the UDMA-66 in mode gust, the AGP 4X (but does not include a slot AGP, from where impossible to replace the graphic accelerator integrated), but not the management of DRDRam. Including a graphic circuit of type I740 (a graphics processor INTEL 8MB 3d), it is reserved for the CELERON. It is replaced in September 2000 by the i815.

8.6. ALI chipset Aladdin TNT2.

Taking again the functionalities of chipset P6ALI, it integrates the graphics processor TNT2 of nVIDIA.

8.7. VIA Apollo Pro 133 and Apollo VCM133. (Pentium III) and Apollo KX133 and Apollo KT133 (Athlon and Duron)

This circuit left at the end of 1999 (before I820) manages memory PC133 and east uses for the PENTIUM III. Its performances compared to an identical configuration containing 440BX are 4 to 7 % higher. According to the type of memory (PC133 or VCM133), the chipset is different.

VIA before AMD the first specific circuit of interface Athlon, Apollo KX133 left. This one manages bus EV6 200/266 MHz developed by alpha, as well as the AGP 4X, SDRam PC 133 and PC100 and the UDMA 66. It is used as much in socket 462 as in slot A (Athlon and Duron).

Left during 2000, it VIA Apollo KT133 is delivered in parallel with the KX133. It manages the socket 462 for Duron and Tunderbird. Identical to the KX on many points, it does not manage any more ISA bus ISA, and can be seen like a KX reduced version.

8.8. INTEL i815/815E (Celeron/Pentium II/Pentium III)

With the i810 mitigated success, INTEL leaves in September 2000 the i815. This chipset manages the UDMA 66, bus AGP 4X, but with the difference of the i820, it does not accept the RamBus memories, but well SDRam PC100/PC133.

8.9. VIA ProSavage PM133. (Celeron/Pentium II/Pentium III)

The market of the cheap computers is probably the future. To compete with the i815 INTEL, VIA fate ProSavage PM133. This chipset includes a controller Apollo Pro133 (thus CELERON and PENTIUM II/Pentium III), a controller network Ethernet 10/100, a graphics processor S3 Savage 4 (3d) and S3 Savage 2000 (2d). It accepts the SDRAM 133. It is also compatible with VIA Cyrix III.

8.10. INTEL I840 (XEON)

This chipset is specific to Xeon, it is of structure identical to the i820, but accepts the multiprocessor

8.11. INTEL i820E

With the mitigated success of the i820, INTEL leaves semi-2000 the i815 for the bottom-of-the-range one. To keep a certain superiority on VIA, INTEL leaves the i820E. This one is identical to the i820, but accepts two channels (separate) USB, an interface network, a double controller ATA/100 and one audio controller 6 channels.

Moreover, it includes a slot CNR incompatible with the slot AMR. These techniques make it possible to connect audio systems/modem. In this last case, this one makes it possible to completely start again the PC following a signal modem.

8.12. I850 (Pentium IV)

The i850 of INTEL is associated Pentium IV. It is an evolution of the i820. It authorizes only RamBus. Apparently, it is him which is responsible for the bad performances of Pentium IV.

The i850 is composed of two chips, namely a MCH (Memory Controller Hub) i82850 and a ICH (I/O Controller Hub) i8201BA. The i8201BA also bears name ICH2, one finds it on the i815E for example.

Northbridge i82850 is for its part very nine. It manages the following buses:

- a bus processor 100 MHz Quad Bumped for Pentium 4
- a bus report equipped with two channels of RDRAM
- a bus AGP 4x
- a bus Interlink for Southbridge

The i82850 manages only the RDRAM (Rambus). It has two channels RDRAM (just like the i840 for Xeon), and can thus reach two modules of Rambus simultaneously, cumulating the band-width. Thus, with two bars of RDRAM PC800 one arrives at a band-width of 2.98 Go /s. Nevertheless, at the price of RamBus memories, this powerful solution is very expensive.

The southbridge manages two channels Ultra ATA 100, integrates two controllers USB 1.1 (that is to say a band-width of 2x12 Mb /s), a support network 10/100 Mbits and the its AC' 97 out of 6 channels.

 The 82850 is integrated in a package of the type OLGA (Organic Land Grid Array). This package, smaller and which allows a better thermal dissipation, had been introduced by INTEL with Pentium III. Like the 82850 heating rather well, it is overhung of a radiator.

8.14. AMD-760 (Athlon and Duron)

AMD announces in December 2000 the exit of this chipset which manages memory SDRAM DDR (Double Spleen Dated) in rising and downward sides. AMD left the processors Athlon 1 GHz, 1,1 and 1,2 Ghz answering this technology. To my knowledge, AMD does not produce any more a chipset, leaving this work at companies specialized as VIA or nForce. One specific version accept Athlon MP (dual-processors).

8.15. NVIDIA nForce for Athlon and Duron.

NVIDIA, initially manufacturer of electronic circuits for graphics accelerators, leave in June 2001 a new architecture which will be integrated in next the chipset mark.

Like the majority of the recent chipsets, the nForce is composed of two chips: The nForce Integrated Graphics Processor (IGP) like Northbridge and the nForce Media and Communications Processor (MCP) like Southbridge.


The IGP (Northbridge) integrates two controllers independent reports, MC1 and MC2, which makes it possible to double the band-width available when one lays out of two bars of of the same memories capacity (what doubles the rate of effective transfer). With 2 modules of PC2100, one can have 3.96 Go /s thanks to this TwinBank architecture, against 2.98 Go /s for the two channels of RDRAM PC800 managed by the chipsets i840, i850 and i860. The IGP integrates a graphics card GeForce2. Near to GeForce2 MX, this graphics processor has an internal interface of type AGP 8x. The GPU can be decontaminated to accommodate an external graphics card in AGP 4X. 

Another technology integrated in the IGP, the DASP (Dynamic Adaptive Speculative Pre-Processor). It is acted in fact of an intelligent mask integrated into the IGP which benefits from the band-width unutilized memory to charge of the data which would owe beings required later by the processor. The results are obvious, since the activation of the DASP on a platform of the type Athlon 1.2 GHz + DDR makes it possible to gain from 20 to 30% of performances in bench memories and 6 to 8% in the applications.


IGP and MCP are connected via a bus using HyperTransport technology of AMD. The band-width offered by this bus is 800 Mo /s, against only 266 Mo /s for V-Link of VIA and Interlink of INTEL. NVIDIA justifies this vice of band-width by the total of the necessary band-width in worst of the cases by the various elements of the MCP: 513 Mo /s.

The MCP (Southbridge) manages a bus PCI 32 bits, two channels Ultra ATA 100 as well as two controllers USB 1.1.  The MCP also integrates an audio processor hardware (256 votes in 2d and 64 in 3d, compatible EAX2, I3DL2, HRTF and DSL2) which manages from 2 to 6 enclosures and has a coder Dolby DIGITAL in order to send the sound in AC-3 to a system Home Theater via a SPDIF.

Moreover, the MCP has a controller Ethernet 10/100 Bases-T hardware and of a modem 56K emulated in software. The large advantage of controller network 10/100 is to be interfaced with HyperTransport, which manages the isochronous data flows, which allows the data of beings delivered with a band-width and a guaranteed latency time (NVIDIA calls that StreamThru architecture). This offers a real band-width of 10% higher than that offered by boards 10/100 3Com, INTEL or NetGear.

The first implementations of architecture nForce will be the nForce 220 and the nForce 420, which will be distinguished from the support or not from architecture TwinBank (Dual-Channel Memory).

8.16. INTEL i845.

Confronted with the prices of RAMbus memory, INTEL leaves at the end of December 2001 a chipset equivalent to the 850 for Pentium IV but managing the memories Dimm PC133/PC100, the i845. The version i845D, left then, is identical but manages memories DDR. Several equivalent versions follow according to technological projections'. Notice that the 845 do not manage the ATA-133, only the ATA-100.

Diagram and characteristic of the i845

Diagram and characteristic of the i845D

Diagram and characteristic of the i845E

socket 478 socket 478 socket 478
- - Hyper-Treading
FSB 400 FSB 400 FSB 533 - 400
4 ports USB 1.1 4 ports USB 1.1 6 ports USB 2.0
Dimm PC133 (PC 100) DDR 200/DDR 266 DDR 200/DDR 266
Audio AC97 Audio AC97 Audio AC97

Board network 10/100

Board network 10/100

Board network 10/100

Diagram and characteristic of the i845G - 845GE

Diagram and characteristic of the i845GL and Steam Generator for CELERON

Diagram and characteristic of the i845P

socket 478 socket 478 socket 478
Hyper-Treading Hyper-Treading Hyper-Treading
FSB 533 - 400 FSB  400 (845GL) - FSB 533 (845GV) FSB 533 - 400
AGP 4X External graphics processor on motherboard AGP 4X
6 ports USB 2.0 6 ports USB 2.0 6 ports USB 2.0
DDR 200/DDR 266 DDR 266 - DDR 333 DDR 266 - DDR 333
Audio AC97 Audio AC97 Audio AC97

Board network 10/100

Board network 10/100

Board network 10/100

The version 845G and following are versions improved of the 845E on the level of the improved graphic functions called Extreme Graphic. According to Southbridge used, some motherboards (used for the CELERON) could use memories PC133.

© The diagrams are directly reproduced site of INTEL and can evolve/move.

8.17. INTEL 865 and INTEL 875

Confronted with the performances of the processors, INTEL as of other manufacturers of chipsets launched out in the Dual one (also called Twin Bank). This technology uses 2 benches of memories DDR333 or DDR400 in parallel and significantly increases the performances memories of the processor. At the same time, last technology are established on the motherboard like that the SERIAL ATA, the AGP 8X and a technology RAID in certain versions. The i875PE accepts auto-corrective memories ECC. This version is thus more specific for PC the top-of-the-range one of server type for example.

Diagram of I 865P: Socket 478 -  Hypertreading - FSB 533 / 400 - AGP 8X - DDR333/DDR400 - Audio AC'97 - Ethernet 10/100.

Diagrams of I 865PE: Socket 478 -  Hypertreading - FSB 800 / 533 / 400 - AGP 8X - DDR333/DDR400 - Audio AC'97 - Ethernet 10/100 - Option Raid

Diagrams of I 875: Diagrams of I 865PE: Socket 478 -  Hypertreading - FSB 800 / 533 - AGP 8X - DDR333/DDR400 memory ECC (with error correction) - Audio AC'97 - Ethernet 10/100 - Option Raid

8.18. To finish.

The evolution of Chipset goes from pair with that of the microprocessor. Like the internal buses, peripheral and memories are not enough powerful to follow current speeds of the processors, the CHIPSET is the component main thing of a motherboard. Since Pentium, they integrate the majority of interfaces (memory, drunk, controller hard disk and diskette, ports series and parallel, USB...).

In the same family of processor, it is possible to use a higher chipset, while being wary of the multipliers of frequency since generally, the new motherboards manage only base frequencies FSB higher. Conversely, an old motherboard in a family of processors often do not manage the most modern processors by limitation of the chipset, in particular on the level of the FSB. If the FSB of the board is compatible with the FSB of the processor (but multiplication factor not recognized), a Bios flashing can correct the problem.

If you read data-processing reviews, the possibilities of replacing your processor by new more powerful are legions (upgrade). Unfortunately, it is practically never the case without changing motherboard, precisely because of the limitations of the chipset of the motherboard on level FSB for example. We will see it in the chapter upgrade PC

In relation:

Next chapter of the hardware 1 course > 9. Memory for PC

Computer equipment 2: networks, servers and communication

Our data-processing store ybet

Competences with the service of quality in data-processing