Chip sets: change of the leader (a part I)

Implementation of considerable potential possibilities of modern high-powered processors in the big degree depends on their electronic surrounding, for example, from integral chips environing the processor and other radioelements. The given chips and units set necessary working conditions of power supplies and data transfer, that is provide effective operation of the central processor unit. They also carry out electrical and logical links of the processor and other parts of all system of the computer, influencing on the common productivity.

The modern approach consists that the given chips of a surrounding of the processor are usually presented by the specialised chipset of system logic named as a chip set (chipset).

Implementation of potential possibilities of the processor, together with efficiency of its interaction substantially depends on chip set operation with other units and computer subsystems. Therefore the specialised chipset, its inner pattern and functionality should be closely co-ordinated to features of the architecture of concrete variants of processors, with which they are oriented to operation also which should help with implementation of their potential possibilities. Besides, such set forms taking into account various patterns of computers and a possible variety of solved tasks and is a motherboard basis.

Usage of optimally designed specialised set — a chip set is pledge of high efficiency of the computer and on the contrary, application of the nonoptimal chipset of a surrounding of the processor leads to lowering of the common productivity and limitation of functionality of all system of the computer.

The greatest distribution was received by chip sets of corporations of Intel, VIA (VIA Technologies), ALi (Acer Laboratories Inc. — AcerLab.). The deserved popularity was received by their many products. And such chip sets as i440BX AGPset and i440ZX AGPset, developed and released by Intel corporation, became indisputable leaders in systems with processors Celeron and Pentium II/III.

However, despite successes of the specified sets of system logic, recently Intel corporation tests a number of problems with the new chip sets. These problems are generated by excessive hobby for progressive ideas and processing techniques which the corporation has tried to insert all simultaneously. Some miscalculations in the marketing policy have affected also. Competitors who, using the newest computer processing techniques, in short period have released a wide number of the perspective products which have made a worthy competition to chip sets of the corporation of Intel have, of course, taken advantage of these circumstances. Nevertheless, despite of time difficulties, the leader of computer branch — the corporation of Intel has not stopped the efforts routed on development of new, high-powered chip sets. Have been developed and released i810, i810E, i820, i820E, i840. At the heart of these products the newest developments and processing techniques have been used. However these chip sets and could not repeat success i440BX AGPset and i440ZX AGPset. Certainly, there were miscalculations and the errors aggravated with successes of competitors. There were also wrong forecasts. There were also difficulties with partners.

But a manual and engineers of the corporation of Intel have managed to draw correct, constructive outputs. As a result of these efforts there were chip sets i815 and i815E with which help Intel corporation has chance to change position in the market of specialised sets and to return themselves the lost computer boundaries.

That on advantage to estimate all dramatic nature of the situation linked to development of chip sets from i440BX to i815E, it is necessary to consider structure, functionality and problems of the main chip sets, made the big impact on development of computer processing techniques and creation of the modern market koplektujushchih.

The chip set i440ВX (i440ВX AGPset) is optimised for operation in systems on the basis of processors of the sixth generation which processors of Intel Celeron concern, Pentium II and Pentium III. It is the first chip set of the corporation of Intel which architecture is calculated for frequency of the bus of processor Host Bus of 100 MHz — FSB (FSB — Front Side Bus).

The controller of memory built in a chip set supports 64/72-разрядную the memory bus (64 + 8 ECC) and memory of type EDO DRAM or SDRAM with maximum size to 1 Gbytes.

The chip set i440BX, as well as its predecessors, is a synchronous chip set. It means, that frequency of the bus of memory is always equal to frequency of the bus of processor FSB.

The built in controllers of interfaces and a controls support: modes AGP 1X/2X, to 5 arrangements PCI (in addition to I/O bridge — PIIX4/PIIX4E), 2 ports IDE with possibility of usage of mode UltraDMA/33, 2 ports USB; ACPI; WfM and other functions and arrangements.

In i440BX 2 values of frequency coefficient for reception frequency AGP from frequency processor buses (AGP:FSB) — 1:1 and 2:3 are realised . For bus PCI value of such coefficient can be selected from relations 1:2, 1:3, and also 1:4.

It is necessary to underline, that the variant 1:4 is supported not by all motherboards, however it represents the greatest interest for the users, experimenting dispersal modes (overcloсking) units and computer subsystems. Here it is necessary to remind, that a relation 1:3 at the frequency of the bus of processor FSB equal of 133 MHz, provides value of 40 MHz frequency buses PCI. For many arrangements this value is excessive and interferes with correct operation of the arrangements which have been hooked up to the given bus. First of all, it concerns such arrangements, as hard disks. These arrangements are extremely sensitive to speeding up of their operation though some types successfully function at frequency of 45 MHz. It is obvious, that the relation is more preferable to support of a quiescent operation of hard disks and saving of data 1:4, allowing to make successful experiments not only on frequency of 133 MHz, but also even outside of this value. However, considering possibility of usage of the modes characterised by raised frequencies of the bus of the processor, it is impossible to forget about such important arrangement as the videoadapter which is hooked up through bus AGP. Possible for a chip set i440BX 1:1 and 2:3, underlying creations frequency buses AGP, at frequency of the bus of processor FSB 100 MHz there are more than relation , lead to values obviously more than the standard value making 66 MHz. However some modern videoadapters steadily function at the raised frequencies reaching of values of 90 MHz, and for some copies even above.

The chip set i440BX consists of two chips: 82443BX and 82371AV/EB. A chip 82443BX — Host Bridge/Controller PCI AGP (PAC). A chip 82371AV/EB — PCI-TO ISA/IDE Xcelerator (PIIX4/PIIX4Е).