QSFP+ Transceiver, DAC, AOC – Which Is More Cost-Effective?

QSFP+ Transceiver, DAC, AOC – Which Is More Cost-Effective?

For 40GbE direct cabling between two devices using QSFP+ port, there are several options including QSFP+ transceiver option, QSFP+ DAC (Direct Attach Copper) cable, and QSFP+ AOC (Active Optical Cable). Among these options, each of them has its own merits. Today, I’d like to make a comparison between them from the perspective of the costs.

Case 1: Distances Below 5 m

If the transmission distances is under 5 m, like the case that two switch ports are connected within the same rack or between racks located within the same room. The QSFP+ passive DAC cable is recommended. Take the Cisco compatible QSFP+ optics (Fiberstore Brand) for example:

DAC 5m Cisco QSFP-H40G-CU5M Compatible 40G QSFP+ Passive Direct Attach Copper Cable US$ 65.00
AOC 5m Cisco QSFP-H40G-AOC5M Compatible 40G QSFP+ Active Optical Cable US$ 140.00
Transceiver & Cable Cisco QSFP-40G-SR4 Compatible 40GBASE-SR4 QSFP+ 850nm 150m DOM Transceiver US$ 85.00
5M OM4 12-fiber MTP Fiber Optic Trunk Cable for 40GBASE-SR4 US$ 73.00
Case 2: Distances Below 100 m (< 5 m)

For the case that transmission distance is below 100 m but beyond 5 m, the QSFP+ AOC is an ideal choice for use, namely DAC VS AOC, the AOC win. In this case, the QSFP+ passive DAC cable cannot achieve such long reach requirement because of its performance limitation. While the 40GBASE-SR4 QSFP+ transceiver can do this but the cost of the MTP trunk cable is higher. Thus, here, the compatible QSFP+ AOC is preferred.

AOC 100m Cisco QSFP-H40G-AOC100M Compatible 40G QSFP+ Active Optical Cable US$ 250.00
Transceiver & Cable Cisco QSFP-40G-SR4 Compatible 40GBASE-SR4 QSFP+ 850nm 150m DOM Transceiver US$ 85.00
OM4 12-fiber MTP Fiber Optic Trunk Cable for 40GBASE-SR4 over US$ 500.00
Case 3: Distances Above 100 m

If the transmission distance is longer than 100 m, DAC cables and AOCs are usually not recommended. In this case, the 40G QSFP+ modules which are used for short-reach applications are recommended.

Cisco QSFP-40G-SR4 Compatible 40GBASE-SR4 QSFP+ 850nm 150m DOM Transceiver US$ 85.00
Cisco QSFP-40G-SR4-S Compatible 40GBASE-SR4 QSFP+ 850nm 150m DOM Transceiver US$ 85.00
Cisco QSFP-40G-CSR4 Compatible 40GBASE-CSR4 QSFP+ 850nm 400m DOM Transceiver US$ 110.00

In addition to the QSFP+ modules, you may need to select the right cables and patch panels according to your requirements. These costs should be considered in your plan. The detailed prices will not list here.

Of course, all above are rough estimates of the optics. In practical application, more details are included. Users can consult clearly when purchasing. In addition, for short-distance migration to 40 GbE, the breakout DAC cable and AOC could be another good choices. Meanwhile, it should be note that the prices listed above are the product list prices of Fiberstore Website. If you wanna buy, please to real-time prices shall prevail in www.fs.com.

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