Expansion slot

The expansion slot is a slot on the main board that is used to fix the expansion card and connect it to the system bus. It is also called expansion slot and expansion slot. Expansion slots are a way to add or enhance computer features and functionality. For example, not satisfied with the performance of the motherboard integrated graphics, you can add a discrete graphics card to enhance display performance; not satisfied with the sound quality of the onboard sound card, you can add a separate sound card to enhance the sound; motherboards that do not support USB2.0 or IEEE1394 can add the appropriate USB2 .0 expansion card or IEEE1394 expansion card for this function and so on.

At present, the main types of expansion slots are ISA, PCI, AGP, CNR, AMR, ACR, and relatively rare WI-FI, VXB, and PCMCIA dedicated to notebook computers. Historically, MCA slots, EISA slots, and VESA slots have long since been eliminated. The main expansion slot in the future is the PCI Express slot.

The PCI slot is an expansion slot based on a PCI local bus (Pedpherd Component Interconnect). The color of the PCI slot is generally milky white and is located below the AGP slot on the motherboard and above the ISA slot. Its bit width is 32 bits or 64 bits, its operating frequency is 33MHz, and its maximum data transfer rate is 133MB/sec (32 bits) and 266MB/sec (64 bits). Pluggable graphics card, sound card, network card, built-in Modem, built-in ADSL Modem, USB2.0 card, IEEE1394 card, IDE interface card, RAID card, TV card, video capture card and other kinds of expansion cards. The PCI slot is the main expansion slot of the motherboard. By inserting different expansion cards, almost all functions that can be achieved by the computer can be achieved at present. It is a true “universal” expansion slot.

AGP (Accelerated Graphics Port) is developed on the basis of PCI bus. It is mainly optimized for graphic display and is specially used for graphic display cards. The AGP standard has also evolved over the past few years. From the initial AGP 1.0 and AGP 2.0 to the current AGP 3.0, if it is differentiated by the double speed, it mainly experiences AGP 1X, AGP 2X, AGP 4X, and AGP PRO. The latest film version is AGP 3.0, which is AGP 8X. The AGP 8X can achieve a transmission rate of 2.1GB/s, which is twice the transmission speed of AGP 4X. The AGP slot is usually brown (the above three interfaces are distinguished by different colors for the convenience of user identification), and one thing to note is that it is not in the same horizontal position as the PCI, ISA slots, but some This makes the PCI and ISA cards impossible to plug into. Of course, the AGP slot structure is completely different from PCI and ISA, and it is impossible to insert wrong.

PCI-Express is the latest bus and interface standard. Its original name was "3GIO" and was proposed by Intel. It is clear that Intel means that it represents the next-generation I/O interface standard. It was renamed "PCI-Express" after being issued by the PCI-SIG (PCI Special Interest Organization) certification. This new standard will fully replace the current PCI and AGP, and ultimately achieve the unification of the bus standard. Its main advantage is the high data transmission rate, which can reach a maximum of 10 GB/s at present, and there is still considerable potential for development. PCI Express also has a variety of specifications, from PCI Express 1X to PCI Express 16X, to meet the needs of low-speed devices and high-speed devices presently and in the future. The majority of Intel's i915 and i925 series chipsets that can support PCI Express. Of course, it takes a long process to fully replace PCI and AGP. Just like PCI replaced ISA, there will be a transitional process.

When purchasing a motherboard product, the number and type of expansion slots are an important indicator of purchasing decisions. Having multiple types and a sufficient number of expansion slots means that there will be enough upgradeability and device scalability in the future. Otherwise, there will be huge obstacles in the future upgrades and device expansion. This is especially important for beginners. For example, if you are not satisfied with the game performance of the integrated motherboard and want to upgrade to a discrete graphics card, you will find that there is no AGP slot on the motherboard; if you want to add a video capture card, you will find that the used PCI slots are already full. However, the number of expansion slots is not as good as possible. Excessive slots will increase the cost of the motherboard and increase the user's purchase cost, and too many slots have no effect on many users. For example, one slot only needs to be implemented. Office computers with text processing and Internet access are equipped with six PCI slots and are equipped with discrete graphics cards. This is a typical waste of resources. This type of computer can fully meet the usage requirements only with the integrated Micro ATX motherboard. Therefore, the purchase of specific products must be based on their own needs to purchase, in line with their own is the best.