3 ms·
«how are NICs such a bottleneck» Simple: when the packet data does not need to be processed by the CPU. For example a router forwarding network packets at 10 T
by mrb 7y ago
«how are NICs such a bottleneck»
Simple: when the packet data does not need to be processed by the CPU. For example a router forwarding network packets at 10 Tbit/s. The data can stay in the NIC cache as it is being forwarded. No PCIe/CPU/RAM bottleneck here.
Also, EPYC Rome has 1.64 Tbps of RAM bandwidth today (eight DDR4-3200 channels). 10 Tbps is less than three doublings away. It's conceivable server CPUs can reach this bandwidth in 4-6 years.
- GhettoMaestro 7y agoYou still need to account for NIC-to-NIC packet transfers for scenarios where pkt arrives on Phy NIC A and needs to egress via Phy NIC B. Obviously there are better options than just PCIe transport these days.
- Cyph0n 7y agoThe ASR-9000 series can handle up to 3.2 Tbps of L3 traffic per linecard, but this is only achievable because of the dedicated routing ASICs.
- zamadatix 7y ago32 port 400G (12.8 terabit/s) 1u routers already exist today, the conversation is about the NIC at the server <-> network boundary not switching ASICs. The only reason you don't see 400G NICs in servers is the lack of the servers ability to put that much bandwidth over PCIe (the real bottleneck location).