DVI (Digital Visual Interface) has been connecting computers to monitors since 1999. While HDMI and DisplayPort have taken over in many applications, DVI is still widely used on existing monitors, projectors, KVM switches, and professional equipment. Understanding the three DVI variants — DVI-D, DVI-I, and DVI-A — helps you buy the right cable and avoid incompatible connections.
The three DVI variants
DVI was designed during the transition from analog (VGA) to digital video. To bridge both worlds, the DVI standard includes three connector variants that carry different signal types.
DVI-D (Digital only) carries a purely digital signal. The "D" stands for digital. This is the most common DVI type today and provides the best image quality. DVI-D connectors have pins arranged in three rows, with a flat horizontal bar (the "blade") on one side. The pin area next to the blade is empty — no additional pins surround it.
DVI-I (Integrated — digital and analog) carries both digital and analog signals through the same connector. The "I" stands for integrated. DVI-I connectors look similar to DVI-D but have four additional pins surrounding the blade. These extra pins carry the analog VGA signal. A DVI-I port accepts both DVI-D cables (digital signal) and DVI-A cables (analog signal), plus DVI-to-VGA adapters.
DVI-A (Analog only) carries only an analog signal — essentially VGA through a DVI-shaped connector. DVI-A is rare and mostly found on older equipment. If you see a DVI-A cable, it's doing the same job as a VGA cable, just with a different plug shape.
Single-link vs dual-link
Both DVI-D and DVI-I come in single-link and dual-link versions. The difference is bandwidth and maximum resolution.
Single-link DVI uses one TMDS transmitter link with a maximum bandwidth of 3.96 Gbps. It supports resolutions up to 1920x1200 at 60Hz (WUXGA). For a standard 1080p monitor, single-link DVI is sufficient.
Dual-link DVI uses two TMDS links for double the bandwidth (7.92 Gbps). It supports resolutions up to 2560x1600 at 60Hz (WQXGA). If you have a 2560x1440 (QHD) monitor connected via DVI, you need a dual-link cable.
You can visually tell them apart by counting pins. Single-link connectors have fewer pins in the center area (the middle row is partially empty). Dual-link connectors have all pin positions filled — a solid block of pins.
A dual-link cable works in a single-link port (it just uses one link). A single-link cable in a dual-link port will limit you to single-link resolutions.
DVI adapter compatibility
One of the most practical aspects of DVI is its compatibility with other video standards through simple, inexpensive adapters.
DVI to HDMI — DVI-D and HDMI use the same underlying digital signal (TMDS). A DVI-to-HDMI adapter or cable carries the video signal perfectly. However, DVI does not carry audio, so you'll still need a separate audio connection when using a DVI-to-HDMI adapter. These adapters are passive (no electronics inside) and very affordable.
DVI to VGA — Only works with DVI-I or DVI-A ports, because VGA requires an analog signal. A DVI-I to VGA adapter uses the analog pins on the DVI-I connector. This adapter will not work with a DVI-D port (no analog pins available). This is a common source of frustration — people buy a DVI-to-VGA adapter without realizing their graphics card has DVI-D (digital only) output.
DVI to DisplayPort — Requires an active adapter with electronics inside that convert between the two protocols. These are more expensive than simple DVI-HDMI adapters. Direction matters: a DisplayPort-to-DVI adapter (for connecting a DP computer to a DVI monitor) is common and affordable. A DVI-to-DisplayPort adapter (for connecting a DVI computer to a DP monitor) is less common and more expensive.
Maximum resolutions by DVI type
Single-link DVI-D supports up to 1920x1200 at 60Hz. Dual-link DVI-D supports up to 2560x1600 at 60Hz. DVI-I single-link handles 1920x1200 digital or 2048x1536 analog. DVI-I dual-link handles 2560x1600 digital or 2048x1536 analog. DVI-A maxes out at 2048x1536 (same as VGA).
Is DVI still worth using?
DVI remains a perfectly good connection for monitors up to 2560x1600. The digital signal quality is identical to HDMI at the same resolution — your monitor doesn't know or care whether the signal arrived via DVI or HDMI.
However, DVI doesn't support 4K, doesn't carry audio, and doesn't support HDR. If you're buying a new monitor, you'll almost certainly use HDMI or DisplayPort. But for existing equipment — especially office monitors, KVM switches, medical displays, and industrial equipment — DVI cables remain essential.
At Kentek, we carry DVI-D single-link, DVI-D dual-link, DVI-I, and DVI-A cables in lengths from 3 to 25 feet, plus DVI-to-HDMI and DVI-to-VGA adapters.