{"id":4552,"date":"2023-06-16T08:10:02","date_gmt":"2023-06-16T08:10:02","guid":{"rendered":"https:\/\/www.fibermall.com\/blog\/?p=4552"},"modified":"2023-12-08T05:54:30","modified_gmt":"2023-12-08T05:54:30","slug":"what-do-you-know-about-400g-dac-and-aoc","status":"publish","type":"post","link":"https:\/\/www.fibermall.com\/blog\/what-do-you-know-about-400g-dac-and-aoc.htm","title":{"rendered":"What do You Know about 400G DAC and AOC?"},"content":{"rendered":"\n

Data centers, enterprises and high-performance computing environments require resilient and defined 50G, 100G, 200G and 400G cables for interconnecting within and between racks. With the development of 400G technology, 400G direct connect cables for short-haul data center interconnects are now in mass production and on the market, including 400G DAC and 400G AOC.<\/p>\n\n\n\n

\"QSFP-DD\"<\/figure>\n\n\n\n

Currently, 400G DAC<\/span><\/a> and 400G AOC are available in two main package types: QSFP-DD and OSFP, both of which use the 8*50Gb\/s PAM4 electrical modulation format. In addition to the 400G direct cable, there are also 400G Direct Attach Cable high-speed breakout cables and 400G AOC active breakout cables, which use one 400G connector at one end of the breakout cable and several connectors of the same lower rate (total rate of 400G) at the other end. 400G DAC\/AOC types are listed below:<\/p>\n\n\n\n\n\n\n\t\n\n\t\n\t\n\t\n\t\n\t\n\t\n\t\n\t\n\t\n\t\n\t\n\t
Product Category<\/th>Product name<\/th>Description<\/th>Maximum transmission distance<\/th>Application<\/th>\n<\/tr>\n<\/thead>\n
400G QSFP-DD DAC Direct Connect Cable<\/td>QSFP-DD to QSFP-DD DAC<\/td>One 400G QSFP-DD connector on each end, with eight 50G PAM4 electrical channels per connector<\/td>3 meters<\/td>Direct connection between 400G devices<\/td>\n<\/tr>\n
400G QSFP-DD DAC high-speed breakout cable<\/td>QSFP-DD to 2*200G QSFP56 DAC<\/td>400G QSFP-DD connector on one end, 2 200G QSFP56 connectors on the other end, each 200G QSFP56 connector has 4 50G PAM4 electrical channels<\/td>3 meters<\/td>400G-200G Breakout Channels<\/td>\n<\/tr>\n
400G QSFP-DD DAC high-speed breakout cable<\/td>QSFP-DD to 4*100G QSFPs DAC<\/td>400G QSFP-DD connector on one end, 4 100G QSFP connectors on the other end, each 100G QSFP connector has 2 50G PAM4 electrical channels<\/td>3 meters<\/td>400G-100G Breakout Channels<\/td>\n<\/tr>\n
400G QSFP-DD DAC high-speed breakout cable<\/td>QSFP-DD to 8*50G SFP56 DAC<\/td>400G QSFP-DD connector on one end, 8 50G SFP56 connectors on the other end, each 50G SFP56 connector has 1 50G PAM4 electrical channel<\/td>3 meters<\/td>400G-50G Breakout Channels<\/td>\n<\/tr>\n
400G QSFP-DD AOC Direct Connect Cable<\/td>QSFP-DD to QSFP-DD AOC<\/td>One 400G QSFP-DD connector on each end, with eight 50G PAM4 electrical channels per connector<\/td>70m (OM3); 100m (OM4)<\/td>Direct connection between 400G devices<\/td>\n<\/tr>\n
400G QSFP-DD AOC active breakout optical cable<\/td>QSFP-DD to 2*200G QSFP56 AOC<\/td>One end uses 400G QSFP-DD connectors, the other end uses 2 x 200G QSFP56 connectors, each 200G QSFP56 connector has 4 x 50G PAM4 electrical channels<\/td>70m (OM3); 100m (OM4)<\/td>400G-200G Breakout Channels<\/td>\n<\/tr>\n
400G QSFP-DD AOC Active Breakout Fiber Optic Cable<\/td>QSFP-DD to 8*50G SFP56 AOC<\/td>400G QSFP-DD connector on one end, 8 50G SFP56 connectors on the other end, each 50G SFP56 connector has 1 50G PAM4 electrical channel<\/td>70m (OM3); 100m (OM4)<\/td>400G-50G Breakout Channels<\/td>\n<\/tr>\n
400G OSFP DAC Direct Connect Cable<\/td>OSFP to OSFP DAC<\/td>One 400G OSFP connector on each end with eight 50G PAM4 electrical channels per connector<\/td>3 meters<\/td>Direct connection between 400G devices<\/td>\n<\/tr>\n
400G OSFP DAC high-speed breakout cable<\/td>OSFP to 2*200G QSFP56 DAC<\/td>One end uses a 400G OSFP connector and the other end uses two 200G QSFP56 connectors, each 200G QSFP56 connector has four 50G PAM4 electrical channels<\/td>3 meters<\/td>400G-200G Breakout Channels<\/td>\n<\/tr>\n
400G OSFP DAC high-speed breakout cable<\/td>OSFP to 4*100G QSFPs DAC<\/td>400G OSFP connector on one end, 4 100G QSFPs connectors on the other end, each 100G QSFP connector has 2 50G PAM4 electrical channels<\/td>3 meters<\/td>400G-100G Breakout Channels<\/td>\n<\/tr>\n
400G OSFP DAC high-speed breakout cable<\/td>OSFP to 8*50G SFP56 DAC<\/td>400G OSFP connector on one end, 8 50G SFP56 connectors on the other end, each 50G SFP56 connector has 1 50G PAM4 electrical channel<\/td>3 meters<\/td>400G-50G Breakout Channels<\/td>\n<\/tr>\n
400G OSFP AOC Direct Connect Cable<\/td>OSFP to OSFP AOC<\/td>One 400G OSFP connector on each end with 8 50G PAM4 electrical channels per connector<\/td>70m (0OM3); 100m (OM4)<\/td>Direct connection between 400G devices<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n\n\n\n

As can be seen from the table above, the biggest difference between 400G DAC and 400G AOC is the transmission distance, 400G DAC can only support up to 3 meters, while 400G Active Optical Cable can support up to 70m (OM3) or 100m (OM4). This is because the transmission medium used by the two is different, 400G Direct Attach Cable is using copper cable as the transmission medium, while 400G AOC is using optical fiber as the transmission medium. In addition to this, the following differences exist between 400G DAC and 400G AOC:<\/p>\n\n\n\n

Available types <\/b><\/strong>– As far as the current market situation is concerned, there is a wide variety of 400G Direct Attach Cable, while 400G Active Optical Cable active branch optical cables and QSFP-DD to 4*100G QSFP AOC are not in the market for the time being. Therefore, relatively speaking 400G DAC cable can meet more connection needs.<\/p>\n\n\n\n

Volume and weight<\/b><\/strong> – Because optical fiber is smaller and lighter than copper cores, the volume and weight of 400G Active Optical Cable are small compared to 400G Direct Attach Cable. 400G AOC is half the size of 400G Direct Attach Cable and only a quarter of the weight of 400G Direct Attach Cable. In addition, the bend radius of the 400G Active Optical Cable<\/span><\/a> is smaller than that of the 400G QSFP-DD DAC.<\/p>\n\n\n\n

Anti-interference capability<\/b><\/strong> – Since the core of 400G AOC is fiber optic, it is an insulating material and does not conduct electricity. Therefore, it is not susceptible to interference from electromagnetic, lightning, or radio signals during data transmission. While the 400G DAC’s cable is a copper core, which conducts electricity and is susceptible to interference such as lightning.<\/p>\n\n\n\n

Price<\/b><\/strong> – Since fiber is generally more expensive than copper, the price of a 400G Active Optical Cable will usually be higher than the price of a 400G DAC (prerequisite: same level or package). If the transmission distance of 400G DAC can meet your network needs, you can give preference to 400G Direct Attach Cable, which can effectively save costs.<\/p>\n\n\n\n

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