usEnglish       ruRussian       deGerman      

Gigabyte GA-8I945P-G architecture

Evgenie Rudometov

Practically right after declarations the company of Intel of chipsets of the system logic providing support of two-nuclear models of its processors, company Gigabyte has released motherboard Gigabyte GA-8I945P-G. In the architecture of this card a number of perspective processing techniques is realised

It is known, that motherboards concern one of the major accessories of the computer. Not calling in question value of the central processor unit, it is necessary to mark, what exactly the motherboard substantially defines functionality of the computer system. The unsuccessful card – and problems will not release the user, the successful choice will provide maximum implementation of potential possibilities of other accessories.

For this reason manufacturers permanently work over perfection of the architecture of motherboards, expanding a band of their functions. It is usually reached at the expense of usage more perfect shemotehnicheskih solutions and application of the newest chips which number chipsets of system logic (chip sets) concern. Last it is especially important, considering release by the company of Intel of new processors, including recently declared models with two kernels, banked in uniform tank.

For support of a quiescent operation of such two-nuclear models of processors release of the special chip sets which have become by a basis of the newest variants of motherboards was required. It is obvious, that the corporations occupying the upper lines of the list of manufacturers of this sort of production became the first.

Company Gigabyte entering into triple of the main manufacturers of motherboards concerns their number. This manufacturer operatively reacts to market tendencies, offering wide gamma of production, including the newest models of the motherboards calculated for support of high-powered processors.

One their models of these hi-tech products recently announced by company Gigabyte card Gigabyte GA-8I945P-G supporting processors of corporation of Intel is, including topovye variants IntelPentium 4 and the newest two-nuclear models IntelPentium D in konstruktive LGA  775. Besides, functions RAID, gigabitnyj Ethernet, a multi-channel audiosystem, etc. are realised two-channel memory DDRII SDRAM .

Back newest chip set of Intel 945P became a basis of this card declared couple of weeks.

Intel chip set 945P motherboard Gigabyte GA-8I945P-G

Fig. 1. Structure of the computer created on the basis of a chip set of Intel 945P

Intel chip set 945P (i945P) is oriented to creation of high-powered desktop personal computers.

Supports systems with processors of Intel of Pentium 4 with processing technique Hyper-Threading, 90 nanometers created on processing technique , hooked up through LGA 775 plug and working with bus FSB of type QPB (Quad-Pumped Bus) which clock rate can make 133, 200, 266 MHz.

As is known bus FSB of type QPB at clock rate of 133 MHz carries out data transfer with frequency of 533 MHz, an address part — 266 MHz that capacity to 4,2 Gbytes/with provides peak. At clock rate of 200 MHz data transfer is carried out with frequency of 800 MHz, and an address part — 400 MHz. In this mode peak capacity reaches values of 6,4 Gbytes/with. In a mode with clock rate of 266 MHz the transmission frequency of data reaches 1066 MHz.

The bus supports 32-bit addressing that provides to 4 Gbytes of dynamic storage.

Feature of chip set I945P is support of two-nuclear processors of Intel, that formally do not provide chip sets of previous I915 set.

Traditionally for chipsets of system logic chip set I945P consists of two components named Memory Controller Hub (MCH) and I/O Controller Hub (ICH).

The base package of a chip set i945P consists of Intel chips 82945P Memory Controller Hub (MCH) and Intel 82801GB (ICH7). As the second chip the improved variant ICH7 presented by a chip of Intel 82801GR (ICH7R), possessing the expanded possibilities of operation with a disk subsystem of memory can use.

Chips MCH and ICH are jointed by special Direct Media Interface (DMI local bus to a transfer rate to 2 Gbytes/with in each direction: a full duplex.

The MCH component contains the controllers giving interfaces with high capacity in the structure. These controllers control the system bus with data transfer with frequency of 533/800/1066 MHz and two-channel dynamic storage. Besides, they will organise operation of graphic interface PCI Express x16 (to 8 Gbytes/c) and communication facilities with a chip of input/output ICH.

Built in Intel 82945P the controller of processor bus FSB of type QPB supports the bus with clock rate of 266/200/133 MHz that provides data transfer on frequencies of 1066/800/533 MHz.

Built in Intel chip 82945P the memory controller provides support of two-and one-channel functional modes of memory DDR/DDR2 SDRAM (Double Data Rate SDRAM — SDRAM with data transfer on lobbies and back edges of clock pulses of the bus of memory). Support only DDRII SDRAM (400/533/667) is provided. Unlike the previous set of I915 set the chip set i945P does not have possibility of a pattern with usage DDR SDRAM

Maximum size of dynamic storage — to 4 Gbytes. Two-channel memory DDR II SDRAM with frequency of 533 MHz has maximum capacity to 8,5 Gbytes/with, and with frequency of 667 MHz — to 10,7 Gbytes/with.

Chip MCH supports different frequency functional modes for processor and memory buses.

Handle of computer peripheral devices is carried out by the second component of a chip set. Thus it is necessary to mark, that in a chip set i945P chip ICH of the seventh version is used. According to this fact it has received name ICH7 and is presented by Intel chip 82801GB. This chip enters into a base set of a chip set i945P.

The built in resources of a chip of handle of peripheral devices of a base set support: one channel IDE with support ATA 33/66/100 (to two arrangements IDE), four ports Serial ATA 300 (SATA II — to 300 Mb per second), eight ports USB 2.0, to four PCI Express x1, to six PCI (PCI Rev 2.3, 32 bits/33 of MHz), LPC (Low Pin Count), the controller of Intel High Definition Audio with support of three codecs, AC ’ 97 2.3 (to 8 channels), integrated controller LAN (10/100/1000 Mb/s Ethernet), SMBus, APIC, ACPI Rev.2.0, and also other resources and functions.

Except Intel 82801GB as it has been specified above, usage of the expanded version of hub ICH7 — ICH7R (support of functions RAID and to six PCI-E) is possible .

It is necessary to add, that except a chip set i945P Intel company releases a set (more precisely – a chip) i945G with the integrated resources of a drawing. The integrated chip set i945G differs from separate i945P only presence of a graphics kernel of Intel Graphics Media Accelerator (GMA) 950. In the rest both chip sets are identical. Under the company statement graphics kernel GMA 950 twice exceeds on productivity in tests 3DMark05 the previous integrated solution of Intel – GMA 900 (i915G). Support HDTV with the permission to 1080i is declared also.

Structure of package Gigabyte GA-8I945P-G

Fig. 2. Structure of package Gigabyte GA-8I945P-G

According to accompanying documents into package structure standardly enter:

        the Packing box,

        Motherboard Gigabyte GA-8I945P-G,

        the Cover plate of input/output corresponding to specification ATX 2.01, 

        the Compact disc with the software from Gigabyte,

        Cables Ultra DMA 66/100/, Serial ATA, Floppy,

        the Documentation.

The main technical parametres of motherboard Gigabyte GA-8I945P-G

Fig. 3. Motherboard Gigabyte GA-8I945P-G

Fig. 4. Motherboard Gigabyte GA-8I945P-G plugs

The processor

        Support of processors of Intel of Pentium 4 and Intel of Pentium D in konstruktive LGA775 with the system bus of 1066/800/533 MHz and with processing technique Hyper-Threading (HT)

Chip set

        Northbridge: Intel 82945P (MCH),

        Southbridge: Intel 82801GB (ICH7).

Dynamic storage

        Four (1,8 plugs for dynamic storage DIMM,

        Support of two channels DDR II 667/533/400 (DDR 667 in a mode of 1066/800 MHz) SDRAM,

        Maximum size DDRII SDRAM — to 4 Gbytes.


        the Videoadapter in PCI slot Express X16.


        the Audiosubsystem on the basis of codec ALC882 CODEC,

        Support of 2/4/6/8 audiochannels.

Serial ATA


        Four ports Serial ATA 300.



        One port IDE (Ultra DMA 33/66/100).


        Chip GigaRAID IT8212F,

        Two ports IDE (Ultra DMA 33/66/100/133),

        Support RAID 0, RAID 1, RAID 0+1, RAID JBOD.

USB 2.0

        Eight ports USB 2.0 (four – through a cable).


        Gigabitnaja (10/100/1000 Mbit/c) a network subsystem on base gigabitnogo network controller Broadcom 5789.

System BIOS

        Uses Award BIOS (under the licence).

Backboard ports

        keyboard and mouse Ports PS/2,

        One parallel port LPT,

        One consecutive COM,

        Four ports USB 2,

        One port RJ45,

        Six plugs of audio (a 7.1-channel output, a linear input terminal, a microphone),

        One coaxial S/P-DIF an output,

        One optical S/P-DIF an output.

Input/output system

        the Controller of input/output IT8712.


        one PCI slot Express X16,

        two PCI slots Express X1,

        three PCI slots.

Form factor


        the Sizes of 305 mm h 220 mm.

Features of Gigabyte GA-8I945P-G architecture

The motherboard is created according to the existing requirements defined by high-frequency components and requirements energopitanija.

Unfortunately, high efficiency of modern accessories is accompanied considerable teploobrazovaniem. It demands the appropriate resources of cooling used in the architecture of the motherboard. As an example of used solution, it is possible to result chip MCH (a Fig. 5) which structure the controllers which are responsible for link with the processor are built in, subsystems of dynamic storage and video, and also with chip ICH (in this case ICH7).

Fig. 5. A part of Intel chip set 945P chips Memory Controller Hub (MCH) and I/O Controller Hub (ICH7) with cooling resources

Despite modest to existing measures the heat sink sizes, it successfully fulfils the functions. Here it is necessary to mark, that at maximum computing load the heat sink strongly enough heats up, however values of temperature remain in admissible frames. By the way, maximum admissible temperature of tank MCH — more than 80, and ICH7 — more than 100 degrees of Celsius.

It is necessary to mark, that motherboard Gigabyte GA-8I945P-G is oriented as a basis of mass high-powered systems of wide application. The architecture provides support of the newest models of processors of Intel. These models concern topovye variants of Intel of Pentium 4, bar Extreme Edition processors, and also a new class of products — two-nuclear models. Expediently to use these processors working at high clock rates of the bus — 1066 and 800 MHz. However application and less efficient variants presented by processors of Intel Celeron, 533 MHz calculated for the bus is possible .

Motherboard Gigabyte GA-8I945P-G architecture is calculated for usage both one-channel, and two-channel patterns of a subsystem of dynamic storage with DDR units II SDRAM. Without limitations DDR units II 400 and 533 MHz can be applied . In modes with frequency of the processor bus of 800 and 1066 MHz probably usage of DDR units II 667. It is obvious, that two-channel patterns are preferable as provide reaching of a peak value of a pass-band for a dynamic storage subsystem, especially in case of application of DDR units II 667.

One more attribute of high efficiency is PCI Express x16. Graphics solution PCI Express x16 provides speed to 4 Gbytes/with in each direction, that more than in three and a half time exceeds high-speed performance of the best external graphics adapters with interface AGP8X.

For handle of input\output devices the second component which is a part of the used chip set traditionally responds. As this component in Gigabyte GA-8I945P-G Intel chip 82801GB (ICH7), resulted on a Fig. 5 uses .

From features of the architecture it is necessary to mark an audiosubsystem realising processing technique of Intel High Definition Audio. It provides considerable improvement of playback of a multi-channel sound 48 kgts in comparison with traditional solutions AC ' 97. Support of new formats of house cinemas and support of simultaneous playback of several separate sound streams is Besides, carried out. As the codec chip Realtek ALC882 CODEC is used. It is realised eight audiochannels.

The network controller Gigabit Ethernet realised on a chip of controller Broadcom 5789 is built in the motherboard architecture, hooked up through bus PCI Express х1. The given integrated network tools allow to include easily the computer through built in RJ45 (LAN plug in local area network structure.

For the extension of the computer system created on the basis of motherboard Gigabyte GA-8I945P-G, the appropriate slots presented by traditional PCI plugs (to 133 Mb per second) and PCI Express x1 (to 500 Mb per second) are  .

One more feature Gigabyte GA-8I945P-G is the organisation of a disk subsystem of hard disk drives.

The motherboard architecture thanks to support of the component of chip set ICH7 incorporates four ports Serial ATA 300 (four arrangements) and one port Parallel ATA-100 (UltraDMA 100/66/33, two arrangements IDE).

Despite usage of chip ICH7 which does not provide RAID, these functions all the same are realised. It is reached at the expense of application of specialised chip IT8212. By means of the given chip functions RAID 0, RAID  1, RAID  0+1, RAID JBOD are realised    .

For the purpose of the extension of possibilities of the motherboard the additional chip which is ensuring functioning with an additional set of disk drives is integrated into its architecture — GigaRAID IT  8212F. This chip ensures functioning Parallel ATA IDE with support of UltraDMA 133/100/66 protocols, and also functions RAID 0, RAID 1, RAID 0+1, JBOD.

In a Fig. 7 plugs of the disk subsystem which are a part of the architecture of motherboard Gigabyte GA-8I945P-G are presented.

Fig. 7. Plugs of a disk subsystem of motherboard Gigabyte GA-8I945P-G

Considering possibilities of motherboard Gigabyte GA-8I945P-G, it is necessary to mark, that this card supports variety of firm processing techniques. As an example it is possible to mark hardware-software support of the developed system of dispersal (overclocking).

Power supply of units of motherboard Gigabyte GA-8I945P-G is carried out through system of impulse stabilising devices.

In a multi-channel impulse surge protector of the processor (a Fig. 8), traditionally allocated round a processor socket, the considerable quantity of filtering capacitors is applied.

Fig. 8. VRM motherboard Gigabyte GA-8I945P-G

Except this converter, on the card there are additional converters of supply voltage PCI Express  x16 and dynamic storage units (a Fig. 8).

In motherboard Gigabyte GA-8I945P-G architecture possibilities of the hardware monitoring providing the control over supply voltages and operation of cooling fans are realised.

Stability and dependability

In the course of durable testing motherboard Gigabyte GA-8I945P-G worked steadily as it usually and is characteristic for products of this manufacturer.

Motherboard Gigabyte GA-8I945P-G can be recommended a wide range of users as a basis of the high-powered systems oriented to usage topovyh of variants of processors of Intel, including two-nuclear models.

Motherboard Gigabyte GA-8I945P-G is given by the Moscow representation of company Gigabyte

Article is published in log the Computer the Price (Computer Price).

   About Us | Site Map | Privacy Policy | Contact Us | © 2009 By Rudometov.COM