Copper vs Active Optical Cables: Which Is Best for Your Setup?

Not all high-speed cables are created equal. When you're connecting servers, switches, or storage appliances, you’ll often have to choose between traditional copper cables (like DACs or SlimSAS/HD MiniSAS) and Active Optical Cables (AOCs).

Both options support high-speed data transfer—but they solve different problems. Here’s how to decide which is right for your setup.

Copper Cables (DACs, SAS, SlimSAS)

Direct Attach Copper (DAC) and shielded internal cables like SlimSAS and HD MiniSAS use conductive metal (usually copper) to transmit data over relatively short distances.

When Copper Is Best:

• Distances under 5–7 meters
• Lower cost and power draw
• EMI shielding and robustness in noisy environments
• Passive or low-power active implementations

Ideal for:

• Rack-level or adjacent cabinet interconnects
• Internal SAS/SATA/PCIe cabling
• Dense server environments where space and airflow are managed

Active Optical Cables (AOCs)

AOCs convert electrical signals into optical ones using embedded transceivers and fiber optics. They offer much longer reach, lighter weight, and superior bandwidth potential over distance.

When AOC Is Best:

• Distances over 7–10 meters
• Tight cable routing in vertical or overhead trays
• Lower electromagnetic interference
• High bandwidth (40G/100G+) at full length

Ideal for:

• Spine/leaf switch uplinks
• Long-reach data center links
• High-performance computing and AI clusters

Key Differences: Copper vs AOC

• Speed & Distance: Copper works great up to ~5 meters. AOC can stretch 10–100+ meters without signal loss.
• Cost: Copper is cheaper per cable—but heavier, thicker, and harder to manage.
• Power: Copper DACs are often passive (no power). AOCs require active components and power on both ends.
• EMI: AOCs are immune to EMI. Copper is shielded but still susceptible in high-noise environments.
• Durability: Copper is more rugged. AOCs are lighter but more fragile under mechanical stress.

What Should You Use?

• Choose copper if your connections are short, internal, or cost-sensitive.
• Choose AOC if you need reach, flexibility, or bandwidth beyond what copper can support—especially in high-speed switch-to-switch scenarios.

Need Help Deciding? We’ve Got Both.

At Data Storage Cables, we stock and build both high-performance copper assemblies (SlimSAS, HD MiniSAS, MCIO) and Active Optical Cables (AOC) for data centers and performance-critical environments.