* While it is technically possible to run LibreQoS in VM, it is not officially supported, and comes at a significant 30% performance penalty (even when using NIC passthrough). For VMs, NIC passthrough is required for throughput above 1 Gbps (XDP vs generic XDP).
* A CPU with solid [single-thread performance](https://www.cpubenchmark.net/singleThread.html#server-thread) within your budget. Queuing is very CPU-intensive, and requires high single-thread performance.
Single-thread CPU performance will determine the maximum capacity of a single HTB (cpu core), and in turn, the maximum capacity of any top level node in the network hierarchy (for example, top-level sites in your network). This also impacts the maximum speed plan you can offer customers within safe margins.
Below is a table of approximate aggregate capacity, assuming a a CPU with a [single thread](https://www.cpubenchmark.net/singleThread.html#server-thread) performance of 1000 / 2000 / 4000:
* One management network interface completely separate from the traffic shaping interfaces. Usually this would be the Ethernet interface built in to the motherboard.
| Mellanox ConnectX-4 Lx | 10/25/40/50 Gbps | | No known issues. |
| Mellanox ConnectX-5 | 100 Gbps | [MCX516A-CCAT 100G](https://www.fs.com/products/119647.html?attribute=67743&id=3746410) | Extreme heat at high load (50+ Gbps). Use Liquid CPU Cooler kit on chip to avoid overheating. |
| Mellanox ConnectX-6 | 10/25 Gbps | [MCX631102AN-ADAT](https://www.fs.com/products/212177.html?now_cid=4014) | No known issues. |
| Mellanox ConnectX-6 | 100 Gbps | [MCX623106AN-CDAT 100G](https://www.fs.com/products/119646.html?now_cid=4014) | No known issues. |
| Mellanox ConnectX-7 | 200 Gbps | [MCX755106AS-HEAT 200G](https://www.fs.com/products/242589.html?now_cid=4014) | No known issues. |
(*) Intel often vendor-locks SFP+ module compatibility. Check module compatibility before buying. Mellanox does not have this problem.
**We will ONLY provide support for systems using a NIC listed above**. Some other NICs *may* work, but will not be officially supported by LibreQoS. If you want to *test* the compatability of another card, please be aware of these fundamental NIC requirements:
* NIC must have multiple TX/RX transmit queues, greater than or equal to the number of CPU cores. [Here's how to check from the command line](https://serverfault.com/questions/772380/how-to-tell-if-nic-has-multiqueue-enabled).
