A: Why is the PCI interface some long and short?

Recently looking for the PCI interface of the N more strange rare board, incidentally found that the PCI interface there are many kinds, there are long and short, is basically dizzy. So there are so many different shapes that I've found about explaining why the cards are called PCI interfaces.

the difference between PCI and Pci-x

the difference between PCI and PCI-E

Here's what I copied from Baidu:

First, destroy the few of you. "'" Note that the landlord asked is pci-x, not pci-e. ~~~pci-x has nothing to do with graphics cards. ~~

I think the landlord should be a PCI interface. For reasons, see the following decomposition.

First of all, Pci,pci is one of the most common motherboard interface, mostly white (there are also a few motherboards for other colors), general access to some network cards, sound cards, TV cards and other PCI devices.

Mainly said Pci-x,pci-x is with high frequency (expansion equipment), usually rare, generally used for high-performance servers, generally with Gigabit network card, fiber ...

Appearance difference: PCI is shorter than pci-x, concrete appearance reference Picture: Http://img2.zol.com.cn/product/10/396/ceDxBqIoBPJMA.jpg
The two short (white) in the left of the picture is PCI, the middle four long (white) is pci-x

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The following are information about Pci-x:

What is pci-x.

Pci-x is an extended architecture of the PCI bus, which differs from the PCI bus in that the PCI bus must frequently exchange data between the target device and the bus, while the pci-x allows the target device to see the swap only on a single pci-x device, and if the pci-x device does not have any data transfer, The bus automatically removes the PCI-X device to reduce the wait period between PCI devices. Therefore, at the same frequency, Pci-x will be able to provide higher 14-35% performance than PCI.

Pci-x Another advantage is that it has an extensible frequency, that is, the frequency of the pci-x will not be as fixed as PCI, but can vary with the device changes, such as a device working in 66MHz, then it will work in 66MHz, and if the device supports 100MHZ, Pci-x will be working under 100MHz. Pci-x can support 66,100,133mhz these frequencies, and in the future, more frequency support may be provided.

The Pci-x controller working at 66MHz will be able to access up to 4 pci-x devices and, of course, additional devices can be supported if a bridging chip pci-x to Pci-x is added. 66MHZ Pci-x has 533mb/s bandwidth.

All pci-x devices are working under 100MHz Pci-x Bus will only manage up to two pci-x devices, with 800mb/s bandwidth at 64bit bus and 100MHz frequencies.

Pci-x's most luxurious version, working at 133MHz Pci-x will provide stunning 1066mb/s bandwidth, and, of course, only 1 pci-x devices are supported at this time. But for some devices that require a lot of bandwidth, such as fiber-optic interfaces, Gigabit Ethernet interfaces, and so on, Pci-x 133 will improve a number of advantages.