• What is the north and south bridge in motherboards. North and south bridge on the motherboard

    Hello, dear readers of the blog site. I haven’t said anything about computer hardware for a long time. Today we will talk about the chipset. A chipset (from the English Chipset) is a set of chips that exists in any computer, no matter whether it is a laptop or a desktop PC, and with the help of which all devices connected to the computer interact at the moment to the motherboard. The chipset can be said to be the central connecting node on the .

    The chipset, in turn, consists of two main components - north and south bridges. The north bridge includes a RAM controller, a video processor, and DMI and FSB bus controllers. The South Bridge is responsible for the “input/output” ports - that is, for the operation of all kinds of peripheral devices (printer, scanner, flash drives, external hard drives etc.), as well as for work basic system"input-output" (BIOS).

    The North Bridge determines the type of processor that will be installed in the processor socket on the motherboard, determines its frequency, number of cores and other parameters. It cannot happen that a modern processor model will be installed in the socket, but the chipset will be outdated and will not be able to support this processor; there must be a clear connection in this parameter.

    By the way, the words “northern” and “southern” in the names of bridges are there for a reason, they carry important function- indicate the location of these bridges relative to the upper and lower edges of the board (from above, as it were, north, from below, south). In the image above, you can see that the north bridge is located exactly between the connectors for RAM and video card (blue connector), and the south bridge, in turn, is as close as possible to the ports for connecting external devices.

    The fact is that the closer the chipset chips are located to other components motherboard, the faster the interaction between them occurs; roughly speaking, the speed of data exchange increases with decreasing distance. It turns out that there are no trifles here, everything makes sense. In addition, this arrangement allows you to create motherboards of the smallest sizes, including for laptops and netbooks.

    You may have noticed that on modern motherboards Northbridge may be missing as such. Nowadays, it is increasingly possible to encounter a situation in which the northbridge is structurally moved to CPU, which significantly saves space on the motherboard, and just as significantly complicates the design of this board itself, which ultimately cannot but affect its cost, and not for the better.

    So, as mentioned earlier, the motherboard chipset consists of two parts, the north bridge and the south bridge. They exchange data with each other via the DMI (Direct Media Interface) bus, which is clearly visible in the diagram (Figure 2 from the beginning of the article). The FSB (Front-Side Bus) bus is responsible for connecting the processor to the northbridge; the higher its operating frequency, the faster the computer will work.

    By the way, Intel company developed a new QPI bus, which replaced the outdated FSB. Intel developed it in response to the new bus from AMD - HT (Hiper Transport). Bandwidth QPI bus (25.6 GB/s) has increased compared to the outdated FSB (8 GB/s). Previously, AMD had LDT (Like Data Transport) instead of the HT bus.

    Please note that cooling radiators are installed on the chipset, since it can get very hot during operation, especially under peak load. Typically, the more expensive the motherboard, the more attention is paid to all cooling elements (more radiators, radiators themselves larger size and the metal from which they are made is better).

    One more interesting point is that the chipset and for which the motherboard is designed are produced by the same company. In other words, if your processor, for example, is from AMD, then the motherboard chipset was made by the same company. In fact, there are not two of these companies, as is commonly believed (Intel and AMD), but six, or even more. It turns out that ATI and Nvidia not only make excellent chipsets, but also excellent ones.

    There are two more manufacturers that have generally bypassed fame and general recognition, these are the companies SIS and VIA. As far as I know, these two companies are engaged only in the production of chipsets and their chipsets are extremely rare on sale. And yes, there are two more much less well-known chipset manufacturers, to be honest, I don’t remember what they are called, but they produce chipsets mainly for server motherboards.

    So, I propose to summarize all of the above:

    • The chipset affects everything that depends on it, namely, the type of RAM, the type of processor, the version of USB, SATA and other ports, what BIOS will be on the motherboard, etc. Therefore, to the question “Which is the best main component in the system board?", you can safely answer - “Chipset” and no one can blame you for answering incorrectly.
    • Please note that the more expensive the motherboard, the better the chipset it will have. The level of built-in sound and network cards also depends on the chipset. For more expensive models The sound chip on board plays music much better (“cleaner”, bass is deeper and richer) compared to budget models.
    • There is only two types of chipsets: in the first case it is presented in the form of a south and north bridge, in the second case - on the motherboard we can only observe south bridge, and the northern one is hidden in the processor (a more modern version).

    If you don’t know what chipset is on your motherboard, and you don’t have paper documentation for it at hand, you can use free program"CPU-Z". It will display the manufacturer and model of your chipset on the “Mainboard” tab in the “Chipset” column. By the way, if it seems to you that your chipset is already outdated and you suddenly want to change it, then no matter how much you try, you won’t be able to do this, because these chips are “tightly” soldered into the motherboard. I hope I was able to explain to you what is a chipset. Thank you.

    Many of you have heard the phrase: “The South Bridge burned down and cannot be restored!” Advanced users they will immediately understand what we are talking about, but beginners will wonder where I got some kind of bridge on my computer? I’ll tell you right away that you have two of them, there is also the North Bridge. It is these bridges that we will talk about.

    Of course, you can go to the Wikipedia website and find out what the south bridge and north bridge are, but I decided to write in my own words, as I understand it.

    “The north and south bridges of the computer (or, more correctly, the motherboard) are two main functional controllers that are responsible for the operation of all components of the motherboard and are called a chipset.”

    Let's look at them separately. Let's start with the north bridge.

    Northbridge is a bridge that is connected via a bus Front Side Bus directly to the processor, abbreviated as three letters FSB. Typically the northbridge contains a memory controller that assists the processor quick access to memory. The North Bridge is also connected to Accelerated Graphic Port, abbreviated AGP or PCI Express . One of the main functions of the north bridge is to ensure interaction between the motherboard and the processor, as well as determine the operating speed. Part of the northbridge in many modern motherboards is the built-in video adapter. Thus, functional feature The north bridge also controls the video adapter bus and its speed. The north bridge also provides communication between all of the above devices and the south bridge.

    South Bridge - connects to the North Bridge, it is slower than the North Bridge. Buses such as, PCI, USB, SATA, IDE controllers etc. Currently two types of chipsets are available for products INTEL And AMD. The board also has a processor socket, connectors for installing RAM, TV tuners, network cards, sound cards etc.
    In addition to the above IDE, SATA, USB, LAN and other things, the south bridge is also responsible for the SM bus (used to control fans on the board), DMA controller, IRQ controller, system clock, BIOS, APM and ACPI power supply systems, LPC bus Bridge.

    As a rule, the failure of the south bridge puts an end to the life of the motherboard. It is the south bridge that is sometimes the first shield to take the “blow.” Due to technological features, this is so. The reasons for the “death” of the south bridge are an order of magnitude greater than those of the north bridge, because it works directly with “external” devices. So, common cause failure of the South Bridge is a simple overheating caused by a short circuit, for example, of the USB connector. Or power failure hard drive. Because in most cases the southbridge is not equipped with a system additional cooling, it overheats and burns out.

    Symptoms of malfunction

    • When you turn on the laptop or computer, the cooler starts to rotate, the indicators light up, there is no access to hard drive, there is no image on the screen
    • Laptop, computer may turn off after work in a few seconds
    • After switching on it goes into a cyclic reboot
    • Keyboard, touchpad, USB ports refused to work
    • Incorrect image or its complete absence (sometimes there is when connecting a monitor)
    • The equipment starts to turn on only after several attempts

    For different manufacturers and models have different symptoms of malfunctions, which can only be substantiated after detailed diagnostics.

    Reasons for the breakdown of the North and South Bridges

    The cause of the malfunction can be many factors, such as:

    • Overheat. The most common reason. May occur due to untimely cleaning and replacement of thermally conductive lubricants.
    • Factory defect of the chip. A less common problem, but also has a right to life. There are even laptop models where the manufacturer himself declared low-quality chips, such equipment will sooner or later be 100% repaired (already modified chips are installed as replacements without any problem)
    • Liquid ingress. When liquid gets in, the legs create short circuit, which leads to chip failure.
    • Physical deformation. When dropped, some balls may come off the system board, and just one ball is enough for the laptop to stop working completely
    • Voltage surge. For example, from a broken battery or power controller

    Methods for repairing the South and North Bridges

    The concept of repair as such comes down to only one thing, complete replacement chip for a new one. Since this is a complex technological device, its repair has no right to life. A reservation can be made only in cases where we are not talking about the failure of the chip itself (peeling of the microcircuit from the substrate / burnout of elements), but about contact balls lagging behind the board contacts (however, this rarely happens, more often due to physical impact).

    Note, however, that under normal conditions there is no reason for increased heating of the south bridge, but remember that the south bridge is responsible for many devices that could contribute to its overheating and combustion.

    Be careful.

    That's all. Thank you for reading the article. I hope it was useful to you.

    So, first, a little theory.

    A common laptop failure is a burnt out south bridge. Our clients who hand over laptops for repairs ask the question, what is the south bridge responsible for in a laptop? To answer that this is a south bridge and clarify this popular question, we decided to write a short commentary about this popular microcircuit.

    South Bridge– translated from English (Southbridge) – no less important is the controller microcircuit that ensures operation large number functionality of a modern laptop or PC. If your IDE, SATA, USB, LAN, BIOS, APM and ACPI power supply systems, LPC Bridge bus, Embeded Audio, SM bus (responsible for the rotation speed of coolers), DMA controller, IRQ controller have stopped working, you can be sure , that you need to change (resolder) the south bridge. This microcircuit, although not as productive as the north bridge, also performs a number of vital functions. necessary for a laptop functions. The south bridge transmits data to the north bridge, which in turn sends it to the processor for processing. In older laptop models, the tasks of this chip also included data processing on PCI buses, PCIe and ISA. Can be rephrased from technical to simple spoken language that the southbridge is at the forefront of dealing with the user and external technical irritants, such as, for example, installing a faulty laptop USB flash drives First of all, it will jeopardize the operation of the south bridge, which could easily burn out because of this. Short circuits of any of the above ports lead to an increase in the temperature of this microcircuit, which often does not have additional cooling, which leads to overheating.

    Southbridge is a function controller known as I/O Controller Hub (ICH). Presented as BGA chip, soldered to the motherboard which connects peripherals from the CPU via the North Bridge, for example, keyboard, touchpad, USB, COM, LPT ports, etc.

    Why did the laptop's south bridge burn out?

    The South Bridge often breaks down. And the most common symptoms south bridge burnout This:

    • The laptop does not turn on, but the power indicators light up, but there is no image
    • When you turn on the laptop, the indicators light up, but hard drive is not detected and the screen does not display an image
    • The laptop does not boot, there is an image, but windows does not boot
    • laptop freezes while working
    • Keyboard, mouse, touchpad, USB ports do not work
    • Laptop freezes, overheats and shuts down
    • a few seconds after turning it on, the laptop turns itself off or instantly reboots
    • The laptop can only be turned on after several attempts
    • The battery either does not charge at all or does not charge completely
    • incorrect information about the total charge level is displayed
    • when correct installed drivers and no speakers included beep or there are problems playing audio
    • Wi-Fi or network card does not work

    Main reasons failure of the laptop's south bridge- this is a misuse USB port laptop. For example, connecting devices from unknown manufacturers, devices with high power consumption, unsafe removal, etc.

    Of course, we should also not forget about mechanical damage. A typical and very common example is when a laptop fell on the floor. Spilled water that got inside the case or simply direct physical contact - all these are reasons that can also have a negative impact on the motherboard and your laptop.

    Since we have to highest voltage, overheating a laptop can also damage it quite quickly. short time. This can be avoided through prevention, namely: timely prevention,.

    Self-repair of the south bridge

    If you decide to repair a failed microcircuit yourself, you will need the following tools:

    • hair dryer with good hot air flow
    • stencil
    • calibrated balls
    • screwdrivers
    • soldering station
    • solder paste

    Having disassembled the laptop and removing the south bridge chip, you may find that there are no contact balls on the chip. The task at first glance is simple - to restore good south bridge contact motherboard . First, prepare a stencil, lubricate the chip with flux and secure the chip between the stencil plates. Since the stencil corresponds to the design of the south bridge chip, adding the missing calibrated balls for contact will not be difficult.

    The next stage is warming up with a hairdryer. The hairdryer must be powerful enough to melt the calibrated balls. After the balls are melted, we pull the microcircuit out of the stencil and clean it of flux.

    It is necessary to prepare the motherboard very carefully and carefully. “Patches” must be cleaned and leveled horizontal position, since the correct installation of the south bridge on the motherboard depends on this. If you use a soldering iron, try to carefully avoid touching the protective coating of the board and remove the remaining solder.

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