Ethernet Products
Determine ramifications of Intel® Ethernet products and technologies
5030 Discussions

Only getting half speed with teamed intel adaptors


I have a NAS system that has two new Intel NIC's installed. (Have been using them for the past 3 months or so). I recently realized that the read speed from the raid 5 array in the system was VERY slow compared to the write speed to the system. For example, I get 100-120MB/s write to the Raid 5 array on the NAS box through the two adaptors, however the read speed from the NAS system was 25-50MB/s.

I disabled the teaming and went back to a single NIC on the NAS box and now am seeing 100-120MB/s reads. (Same as all my other systems, and the write speed has stayed the same at around 100-120MB/s)

All systems are running windows 7 enterprise. On the NAS system, the two Intel NICs are:

Intel Pro/1000 GT Desktop Adapter

Intel Pro/1000 PT Server Adapter

Both NICs are running into a Netgear switch where I have configured LAG for the two ports these NICs are attached too.

So, what could I be doing wrong? I was trying to set this up to get the maximum read speed from this NAS server and in fact I am getting the exact opposite, about HALF the speed when I have the teaming enabled.

Anyone have any thoughts? Why would going back to using just the 1000PT give me the 100-120MB/s read again and when they are teamed I'm seeing 25-50MB/s read?



0 Kudos
1 Reply

Configuration of the team mode is fairly straightforward, so I doubt that you are doing anything wrong in the team configuration. I do not know enough about the protocols used between your server and the NAS to make a specific recomendation. I also cannot tell exactly where things are slowing down. There might be something going on at the switch side or inside the system where the two adapters are teamed. The two adapters are connected into the computer differently, one using PCI and one using PCIexpress. There might be some bottleneck inside the system as a result of teaming these two adapter types.

You might want to check out the performance tuning discussion and suggestions at

Another thing is to try some of the other teaming modes. Check to see if setting the team mode to static link aggregation mode works. Or you could try a teaming mode that is not dependent on switch groups such as Adapter Load Balancing. See if any of these modes give you the performance you are looking for.

Another possibility is trying a dual-port adapter in the PCIexpress slot and teaming the two ports. That would eliminate any bottlenecks caused by the system or by using adapters with different features. Of course the downside is you would only have partial redundancy on the ports compared to complely separate adapters. Or if you have another empty PCIexpress slot, you could use two single-port adapters.

You can also read more about the different teaming modes at See the related links at the bottom of the page for some other resources.

I hope some of my comments are helpful to you. I am looking forward to hearing about what solution you use.

Mark H