Cheap Desktop 400GbE Switch MikroTik CRS804-4DDQ-HRM Review

Networking Today, we are taking a look at the MikroTik CRS804-4DDQ-hRM. We have a number of these now and have been running our RDMA network backend for the 8x NVIDIA GB10 cluster for several months now, using one. We also have an NVIDIA GB300 Station cluster running on another (using DR4 optics). The exciting part of this is that there are four 400GbE QSFP56-DD ports for a total of 1.6Tbps of network bandwidth. The list price is $1295, but these often sell at a street price of $1100 or so, making this under $0.70/Gbps. Putting that into perspective, it is like an 8-port 1GbE switch for only $5.50 per Gbps. While $1100 is not a low number, on a $/Gbps basis, this is actually really cheap for a new switch. If you want to purchase these, they are in high demand, but we bought ours from B&H (Affiliate link). MikroTik CRS804-4DDQ-hRM External Hardware Overview Starting off, this is a half-width switch at only 218mm wide but 387mm deep. For those with small lab half-width switches, it will be challenging to fit many of them due to the depth. We will show side-by-side mounting options later. The biggest feature, by far, is the high-speed port configuration. There are four QSFP56-DD ports for 4x 400GbE, giving us our 1.6Tbps of switching capacity. As a quick note, these are not the QSFP112 ports you would find in something like the NVIDIA GB300 station. These are not the OSFP ports you would find in higher-end switches like the NVIDIA Spectrum-X series or many ConnectX-8/ ConnectX-9 cards. If you are looking for DACs and optics, the QSFP56-DD is what you want. While four ports may seem limiting, you can split them into 2x 200GbE QSFP56 ports, and more. This just gives you an easy path to 400GbE ports. There are also two 10Gbase-T management ports that connect to the management processor rather than the switch chip. Next, we get a console port for serial management. There is also a reset button on the front of the switch. On the sides, we get mounting holes for rack ears. On the rear, we get power supplies and fans. The power is redundant with two Gospower 350W power supplies. We would not expect these to ever hit 350W in operation. The two fans are also hot-swappable. With the unit, we get rack ears for mounting either in a half-width or standard 19″ rack. On the bottom, we get a label but not much else. Next, let us get inside the switch to see how it is built.