Is there a performance hit for having more than one NIC active in your computer?

Question

Allot of Machines have multiple NICs built in but does using more than one decrease over all system performance? I am just wondering if anyone has ever done any benchmark tests.

Answer 1

Have you ever heard the term "load balancing"? It all depends what you're using the NIC for in your computer. Are you going to make it a server? Are you going to run an ethernet storage device such as a Buffalo? You haven't given me enough information to make an accurate determination. So, in this case the answer is yes and no.

Answer 2

NIC CPU utilization will be the same with no other resources active under the same load as with significant resources.

A gigabit nic will cause significant cpu loading if you reach 50% total throughput on a 2 ghz machine. Way to find out is watch performance monitor.

Let your system calm down. Run traffic through the card (preferably same type of traffic you would be running under high CPU load)

If you see less than 5 %, then its a light load, and no it will not decrease over all performance.

To answer your quesiton directly, ANY resource will have an effect or overall systep performance, but the question really is; is it significant?

If you use the cards to pass same amount of traffic and you're less than 5% cpu, the answer is, no significant performance. You really wont start noticing a drain unless something takes 15% or more CPU.

Answer 3

Whenever you run more devices you tie up more capacity. Therefore the simple answer is yes, you take a performance hit when you do this.

However, the processor capacity, the NIC traffic, etc all come into play. If there is little traffic you will not see it.

Answer 4

I never noticed anything. And im sure there isnt if you are only using one anyway