Minimum CPU to bridge 10G traffic?


#1

I’m looking to bridge 10G Ethernet traffic between a Broadcom 10GBase-T NIC and an Intel SFP+ NIC. How much CPU would this require? Could it be done with something as old as an i3-2100?

Note, I’m not interested in any higher-level features, just L2 bridging. Thanks!


#2

Why do you want to use a router to bridge?


#3

Because I need to extend a layer 2 broadcast domain, and VyOS can do that for free with hardware I already have? Not sure I understand your question. I’m already doing this elsewhere, but in a VM with a much more powerful CPU.


#4

I was just thinking it may be a better network design using a switch doing L2 bridging at 10 G speed. Probably more than two interfaces could be convenient also :wink:


#5

Oh sure, I could get a switch. But this is a home-based small business, so every penny matters, and like I said I’ve already got the NICs on hand. I also only need two client ports (one SFP and one RJ45) and one RJ45 uplink port. I can get a SFF PC with two PCIe x16 slots for as little as $65; the cheapest possible switch is the D-link at $200, and it only has two 10G RJ45 ports.

The only question is whether the i3-3240 in that $65 SFF PC is enough to forward traffic at anything close to line speed. I went ahead and bought it, because the seller has a decent return policy, so I guess I’ll find out!


#6

Hello, @deafen!
It is really hard to predict such things, as this very depends on traffic type, network equipment and even configuration of a motherboard.
That’s why the answer can be got only after real tests. If you do them, please share results with us. This will be interesting.


#7

You will always lose performance switching in software vs ASIC, but I’ve hit 8-9 Gbps with 2 cores on an e5-2670. The VyOS was a VM and the iperf hosts used for testing were both physically connected to the vmware host running the VyOS. I bet you will see great performance with that chip.

For comparison, your chip is over 200 passmark points ahead of mine on a single thread.
https://www.cpubenchmark.net/cpu.php?cpu=Intel+Core+i3-3240+%40+3.40GHz&id=765
https://www.cpubenchmark.net/cpu.php?cpu=intel+xeon+e5-2670+%40+2.60ghz