How Far Can You Run SDI? Max Cable Distances by Resolution

One of the most practical questions in any wired video setup is also one of the most misunderstood: how far can I actually run this SDI cable before the signal falls apart? The answer isn't a single number — it depends on the data rate, the cable quality, and the connectors. Higher resolution means shorter maximum runs. Here's what you can realistically expect, and when to stop fighting copper and switch to fiber.

We've been running cable for professional video and broadcast for over 45 years, including 4K PTZ studio installs where cable distance is a make-or-break detail. These are the real-world numbers.

The Core Rule: More Data, Less Distance

SDI signals degrade as they travel down coax, and higher data rates degrade faster. That's the whole story in one sentence: the more bandwidth you're pushing, the shorter the cable can be before the signal becomes unreliable. A cable run that's rock-solid at HD might fail completely at 4K — same cable, same length, just more data.

Approximate Maximum Distances

These figures assume good-quality coax (think Belden 1694A-class cable for HD/3G, and premium 4K-rated coax for 12G) with quality connectors. Treat them as practical ceilings, not guarantees — real-world results vary with cable grade, connector quality, and installation:

SD-SDI (270 Mbps): up to roughly 300 meters (about 980 feet).

HD-SDI (1.5G): up to roughly 130–140 meters (about 425–460 feet).

3G-SDI (1080p60): up to roughly 120 meters (about 390 feet).

6G-SDI (4K30): up to roughly 80–90 meters (about 260–295 feet).

12G-SDI (4K60): up to roughly 70–75 meters (about 230–245 feet) on premium 4K-rated coax — and significantly less on thinner or cheaper cable.

Notice the pattern: moving from HD to 4K roughly halves your usable distance. A 100-meter run that's comfortable at 3G is past the reliable limit at 12G.

Why Cable Quality Changes Everything

Those distances assume good cable. Drop to thin, cheap, or poorly shielded coax and they collapse — a bargain 12G cable might only give you a fraction of the premium figure before the picture drops out. For 12G in particular, cable grade matters enormously: the difference between standard coax and premium 4K-rated coax can be the difference between a 30-meter and a 75-meter usable run. This is also why thicker coax (lower-gauge, like RG6 or RG11 grades) outperforms thin patch cable on long runs — more copper, less loss.

Connectors and Installation Matter Too

A cable is only as good as its terminations. Poorly crimped or low-quality BNC connectors introduce signal reflections that eat into your distance budget, especially at 12G. On permanent installs, properly terminated premium connectors are worth the small extra cost. Sharp bends, kinks, and running alongside power cables also degrade the signal — good installation practice effectively extends your usable distance.

When to Switch to Fiber

When a run exceeds what copper can reliably handle — generally beyond about 70–100 meters at 4K, or any time you need hundreds of meters — the answer is fiber. SDI-over-fiber converters turn the signal into light, which travels far further with virtually no loss: hundreds of meters to several kilometers depending on the system. The tradeoff is cost: a pair of SDI-to-fiber converters (one at each end) typically runs from a few hundred dollars to over a thousand, plus the fiber itself. But for a long stadium, arena, or campus run, it's the only reliable option — and far cheaper than a failed broadcast.

The Cost-Distance Tradeoff

Short runs are cheap and simple: a factory BNC coax cable handles most setups for $10 to $40. The expense climbs when distance and resolution climb together — premium 12G-rated coax for long 4K runs costs more per foot, and once you cross into fiber territory you're adding converter hardware at each end. The smart move is to plan the run before you buy: know your distance and resolution, and choose the cable grade (or fiber) that comfortably clears it, rather than discovering the limit on shoot day.

For the full breakdown of which SDI standard carries which resolution, see our companion post on 3G vs 6G vs 12G SDI.

If you're planning a wired multi-camera, 4K, or PTZ system and want the cabling designed to actually reach, get in touch — we design and install this infrastructure for a living.

From Mr. Camera. Las Vegas video production since 1981.