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SFP DAC cable is made of high speed passive twinaxial cable with SFP module at both sides, also called SFP to SFP cable. Due to its low latency, high bandwidth, low power consumption (passive cables consume nearly zero power), and high cost-effectiveness, SFP direct attache cables are widely utilized for short-distance interconnects within or between adjacent racks in data centers, such as connecting servers to ToR switches, or linking storage devices.
Below, we will briefly outline the advantages, application scenarios, specifications, and limitations of SFP DAC cables in data center interconnection.
Why are SFP DAC cable widely used in data centers?
- Low cost: Compared to the combination of SFP modules and fiber optic patch cables, DAC cord is cheaper solution.
- Low power consumption: Passive DAC do not require external power supply, making them energy-efficient and environmentally friendly.
- Low latency: DAC copper cable connection results in lower latency compared to photoelectric conversion.
- Suitable for short distances: Especially suitable for short-distance transmission within 5-7 meters, making it the preferred choice for connecting top-of-rack (ToR) switches and servers.
Common DAC Application Scenarios
- Rack interconnect: Connecting servers to top-of-rack (ToR) switches.
- Storage networking (SAN/NAS): Connecting storage devices to high-speed switches.
- High-performance computing (HPC): Connecting compute nodes to meet ultra-high throughput and low latency requirements.
SFP DAC Cable Types for DCI
The SFP DAC cables in data centers support a variety of data rates to accommodate diverse network architecture requirements, the common types are as following:
Short-reach, high-bandwidth, high-speed connectivity for next-generation hyperscale data centers.
SFP Direct Attach Cable Limitations
Although SFP direct attach cable offer distinct advantages, they are limited by a short transmission distance (typically not exceeding 5 to 7 meters). Consequently, they cannot be used for inter-data center connections or long-distance links; for distances exceeding this range, Active Optical Cables (AOC Optical cable) or fiber optic module paired with premium line patch cord must be utilized.
