Not at "low speeds" but at line rate it requires a lot more CPU power to process all of those packets which often leads to drops. These drops specifically are c

Not at "low speeds" but at line rate it requires a lot more CPU power to process all of those packets which often leads to drops. These drops specifically are called RX ring/fifo overflows/overruns and happen when the NIC enqueues more then rx_ring_size packets before the OS initiates a DMA of incoming packets from the NIC to RAM. I suppose if you point a 10Gbps UDP stream at 1Gbps NIC there will be drops but these drops will happen at the switch not at the interface which is a different type of dropping.