Expansion Cards Part 3: PCI Express

In the first two tranches of this series of Tech Tips, we took a look at PCI and AGP, without doubt, the most common expansion slots on a PC today. With some significant improvements in both PCI Express is intended to replace them, and offer a new level of performance. PCI Special Interest Group (PCI-SIG) with AGP and PCI, PCI Express development can be attributed to Intel. This time, on the other hand, has been associated with some other major find in the industry such as Microsoft, IBM and Dell. Even if it is now known as PCI Express, which was not his first choice of name. If it were not for PCI-SIG, the committee that oversees the PCI standard, it could refer to this new format 3GIO (third GenerationInput / exit). PCI Express development se basa en el PCI and AGP, but the physical connections are not interchangeable, and we will see that this is not the only difference. In the PCI standard, data from different units that travel on a bus shared system. In the standard AGP, a dedicated point-to-point interface transfer of data from the graphics card to the system. PCI Express-based approach to the transfer of data collection includes both directions, the number of connections that carries data in packets, for example, a network connection works. The data from a PCI Express will no longer have to travel in a bus or a dedicated connection, but you can use a combination of these two tracks the number of connections to optimize performance. The methods and routes link does not ring as something technical, but has a special significance with PCI Express. A link is the physical connection between PCI Express devices, which may consist of several paths to send and receive data independently. Links can be composed of 1, 2, 4, 8, 12, 16 or 32 channels, configuration and allows flexibility in the allocation of many trails that are necessary for a particular device. There are obvious advantages of this approach, and some of the most significant include the following points? Each PCI Express is devoted to communication between two points, so there is no exchange of ancho de banda. PCI is more important bottleneck that all devices share is equivalent to one lane, and all ancho de banda must also be shared. More channels can be assigned to units that the results could benefit from the extra speed and bandwidth. A PCI Express graphics cards can be attributed 16 orbits (also known as x16), while a network can be attributed only 1 track. Each channel to provide a device that increases the potential return, sequences of data up / down each line available to optimize performance. This process of sending the next byte of data available in the next lane is known as data tapes, and obviously multiple paths are better for cases in which a large proportion of data must be transferred quickly. Speaking of graphics cards, another advantage is that more high-performance graphics card can be installed on a motherboard. The flexibility of PCI Express allows two PCI Express x16 slots will be reviewed by two graphics cards, which in the past requires an AGP slot and one PCI slot. And because of limitations in terms of performance, AGP and PCI combination can really be considered as high performance. In more than two x16 which provides dual display of the operation, particularly when graphics cards to support a motherboard NVIDIA SLI technology, the resources of two cards can be stored together for even higher recovery rate on the screen. An example of this type of motherboard can be seen in DFI Lan Party UT NF4 SLI-D. Like the motherboard supports AGP and PCI as a means to allow dual display, some motherboards offer both AGP and PCI Express slot. It is not only gives the user the ability to run two monitors, offers the added advantage of having an upgrade will be completed in stages. If a new PCI Express motherboards can not buy, perhaps, in addition to a new processor, the budget user may not want to spring a new graphics card immediately. As we take the AGP slot available on the boards, as ECS 915P-A, there is no reason to pull the good AGP card only because buying a new motherboard with support for PCI Express. PCI Express graphics cards are very similar to the AGP video cards, with the exception of contact. The physical size and presentation are comparable, and even if prices are not so different. The current range of graphics cards Geeks.com not allow him to compare apples with apples, short, but you can find many of these AGP cards as PCI Express for roughly the same price (or even less money ). For now, markets seem to be running in parallel, but over time a change occurs in favour of PCI Express, which dominate the market. To reduce the production costs of motherboards could be an advantage. Take the example of a network that requires only 1 way to work. If it was a PCI-based network interface cards, follows the standard 32-bit bus would have to work on this device, instead of four titles required for 1 PCI Express. Motherboard Course Design, weigh heavily on this advantage has never been done, and it is possible that the increase so that the advice May require several tracks. Before you take a look the benefits of PCI Express, performance, we'll take a look at the capacity of PCI and AGP. The standard PCI bus has a width of 32 bits, running at 33 MHz, and offers a maximum bandwidth of 132 Mb / s (which must be shared by all devices are connected). AGP 8x a 32-bit bus, which runs at 533 MHz, and provides a maximum (dedicated) bandwidth 2.1 Gb / s. Each PCI Express is capable of 250 Mb / s in each direction, and advances in silicon technology is necessary to become reality, this number can be expected to quadruple. Currently, a 164-pin x16 slot can be expected to provide about 4 Gb / s bandwidth used in both directions, which is almost twice as much 2.1GB / s bandwidth AGP 8x can offer! Certainly an impressive increase, and as technology improves, it will be very interesting to see the performance scale. In the preceding paragraph, I mentioned the runway x16 features 164 pins. Each track is different configurations accompanied by another physical contact, and a copy x16, x8, x4, and X1 can be found here. For an example of the real world, Chaintech VNF4 Ultra Athlon 64 Socket 939 motherboard shows an installation of a x16 slot X1 and two slots. Graphics card is obviously going to take advantage of most of the power and performance available with PCI Express, but as mentioned, other devices will also be able to take advantage of this new standard. The example of a network is another advantage that is not the number of high-performance graphics card can be installed on a motherboardonly can use the PCI-Express, but also see the execution of services. A Gigabit Ethernet adapter will be more likely to actually reach their rated speed by the biggest obstacle is eliminated in the form of slower, less the PCI bus. Other units ancho de banda intensive, such as RAID controllers, you can also expect to get out of the slow PCI bus and find a smooth ride PCI Express. Although PCI devices that require less ancho de banda do not see the performance benefits go to the PCI-Express, as a general rule, greater acceptance of the expenditure that can find these devices change the course of any way, as was the case with the transition from ISA to PCI. The final word greater speed and flexibility of available PCI Express was designed not only to be the successor of AGP 8X, PCI, but also. The immediate increase in performance, older technologies are quite impressive, considering the time and profits will be even more important. Only time will tell how long the transition will take, but in a place not too clear, we will discuss only the motherboard PCI Express, AGP and PCI and will be the path of humble ISA slot. http://www.geeks.com Computer Geeks, http://www.geeks.com/pix/techtips.htm municipalities technology, and help http://www.geeks.com/pix/techtips.htm computer!