The current DVI interface is divided into two, one is the Dvi-d interface, can only receive digital signals, the interface only 3 rows 8 columns A total of 24 pins, of which the upper right corner of a pin is empty. Incompatible analog signal. The other is the Dvi-i interface, which is compatible with both analog and digital signals. Compatible analog signal does not mean that analog signal interface D-sub interface can be connected to the Dvi-i interface, but must be through a conversion connector to use, the general use of this interface card will have the relevant conversion connectors.
Dvi-i
With compatibility issues in mind, the current graphics card typically uses the Dvd-i interface, which allows you to connect to the normal VGA interface via a switch connector. Monitors with DVI interfaces generally use the Dvi-d interface, as such displays typically have a VGA interface and therefore do not require a dvi-i interface with analog signals. There are, of course, a few exceptions, and some monitors have only dvi-i interfaces and no VGA connectors.
So the LCD monitor with DVI interface is not necessarily the real digital liquid crystal display; dvi-d realizes the real digital signal transmission. And Dvi-i take all the above two interfaces, when dvi-i the VGA device, is played the role of Dvi-a, when dvi-i dvi-d equipment, it played a dvi-d role. To be compatible with traditional analog display devices, most graphics cards now use 24 digital signal pins and 5 dvi-i interfaces that simulate signal pins.