82576 igb is slower than 82574L e1000 ???

[dualathlon]

Hi everyone,

I'm working for a SMB.

My company has 2 supermicro servers:

1 server has 2 nics intel 82574L onboard.

1 server has 2 nics intel 82576 onboard.

Switch between servers is cisco 3560-X.

Esxi vswitch is standard. MTU is 1500.

Bandwidth between a desktop machine (broadcom gbit nic), and a VM inside physical server with 82574 (e1000.o driver), is ~110 MBytes/s.

Bandwidth between desktop, and VM inside server with 82576 (igb.o), is ~50 MByte/s.

Bandwidth between VMs, on the same physical server, can reach ~480 MBytes/s.

Tested VM is using vmxnet3 nics, windows 2008 r2. VM's network only slow down when it is placed on sv with 82576.

All tested VMs, physical desktop are belong to the same VLAN.

I've enabled VMDq on 82576 server. No different.

Hypervisor is Esxi 5.0 update 1, build 623860.

Does anyone has the same issue?

What should i do to fix this problem?

Thanks for reading.

[mydearcosmo]

I got the same problem and still looking for an answer. I hope I can still figure it out for myself.

[dualathlon]

I have some test results:

1. vm1 on host1 with 82576, send data stream to vm2 on host2 with 82574L: bw is 50 MByte/s.

2. vm1 on host1 with 82576, send data stream to vm2 on host2 with 82576: bw is 50 MByte/s.

3. vm1 on host1 with 82574L, send data stream to vm2 on host2 with 82574L: bw is 110MByte/s.

4. vm1 on host1 with 82574L, send data stream to vm2 on host2 with 82576: bw is 110MByte/s.

So, the issue lies somewhere on nic's transmit path.

I add an Intel Gbit Pro1000, 82540EM, on the host with 82576. Then set 82540 nic as active link for std vswitch, the 82540 also suffer the 50MByte/s transmit speed issue. Receive speed on 82540 is 110MByte/s.

It seems that the host has some problems with networking. Host motherboard is supermicro X8DT3-LN4F. I'll raise this issue to Supermicro.

Any comment is appreciate.