Question : Should I enable or disable TCP Offload in my Hyper-V R2 environment?

There is quite a bit of information on this online, however I am still unable to completely determine if TCP Offload should be disabled or unabled...  Here's a quick rundown of my setup.

Servers:  Dell PowerEdge R710
NICs:  Broadcom BCM5709

Two host machines are setup in a failover cluster.  Each host has 8 NICs.  1 NIC is dedicated to CSV traffic.  1 NIC is dedicated to Live Migration traffice.  2 NICs are for iSCSI communications.  And 2 NICs are used by Hyper-V for LAN connectivity.  The 8th NIC is unused.  SAN is a iSCSI Dell Equallogic.  2 stacked Power Connect 6224 switches.

This is what has been done on the NICs at this point:

-Installed the Broadcom drivers and BASP utility on the hosts

-Disabled NetBios on the iSCSI, LM and CSV NICs.

-Enabled Jumbo Frames on the iSCSI, LM and CSV NICs.

-Enabled Flow Control on the iSCSI NICs.

At this point I haven't touched TCP Offloading, but it appears to be enabled by default on ALL NICs.  I wouldn't say I'm seeing issues with it enabled, but I'd like to know if there will be improvement if I disable it.  Seems that there is a lot of info out there, some saying enable, some saying disable.  Can anyone she some light on this?


Answer : Should I enable or disable TCP Offload in my Hyper-V R2 environment?

By disabling TCP Offloading your telling the TOE NIC(s) you've dedicated to the iSCSI network to use the CPU to encapsulate and de-encapsulate the iSCSI packets. This may not be a big deal if your CPU utilization is very low and your packet transmit rate is moderate or less. If I remember correctly high iSCSI packet rates would increase CPU utilization by as much as 20%. If don't have any technical reasons to turn it off I would leave it enabled.
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