Hello After reading quite a number of articles on Tcp Offload Engine (TOE) / Chimney Offload (like this article in Windows IT Pro and this tread on Technet) and labbing, I am wondering if there are any guidelines for enabling TOE/Chimney offload for 1 Gb (Ethernet) links. AFAIK, automatic mode on W2K8 R2 only offloads on 10 Gb interfaces. This behavior can be changed by setting the registry item HKLM\SYSTEM\CurrentControlSet\Services\VMSMP\Parameters\BelowTenGigVmqEnabled (DWORD) to value 1. The good question: in what situations does it make sense to turn on TOE/Chimney offload on 1 Gb links? Input appreciated. /Maurice

Hi Maurice, Thanks for posting here. > The good question: in what situations does it make sense to turn on TOE/Chimney offload on 1 Gb links? Just first to confirm if the NIC we use is support this feature otherwise even if we enabled in in OS level , system would still not be benefited by it .After that please verify if the CPU load is quite heavy due to the network transfer. Otherwise, Id rather leave it to disable. Meanwhile , suggestions in the guides below are good for us to get a better understanding: When to use TCP Chimney Offload Because of the overhead associated with moving TCP/IP processing to the network adapter, TCP Chimney Offload offers the most benefit to applications that have long-lived connections and transfer a lot of data. Servers that perform database replication, function as file servers, or perform backup functions are examples of computers that may benefit from having TCP Chimney Offload enabled. To determine if TCP Chimney Offload will benefit an application, run the application with TCP Chimney Offload disabled to establish a performance baseline. While the application runs, capture CPU utilization for each CPU and the network throughput. After you establish the baseline, set the operating system mode of TCP Chimney Offload to either automatic or enabled, as appropriate, and then compare the CPU utilizations and network throughput. Networking Deployment Guide: Deploying High-speed Networking Features http://download.microsoft.com/download/8/E/D/8EDE21BC-0E3B-4E14-AAEA-9E2B03917A09/HSN_Deployment_Guide.doc Performance Tuning Guidelines for Windows Server 2008 R2 http://www.microsoft.com/whdc/system/sysperf/Perf_tun_srv-R2.mspx Regards, Tiger Li TechNet Subscriber Support in forum If you have any feedback on our support, please contact tnmff@microsoft.com.Tiger Li TechNet Community Support

Hi Maurice, Thanks for posting here. > The good question: in what situations does it make sense to turn on TOE/Chimney offload on 1 Gb links? Just first to confirm if the NIC we use is support this feature otherwise even if we enabled in in OS level , system would still not be benefited by it .After that please verify if the CPU load is quite heavy due to the network transfer. Otherwise, Id rather leave it to disable. Meanwhile , suggestions in the guides below are good for us to get a better understanding: When to use TCP Chimney Offload Because of the overhead associated with moving TCP/IP processing to the network adapter, TCP Chimney Offload offers the most benefit to applications that have long-lived connections and transfer a lot of data. Servers that perform database replication, function as file servers, or perform backup functions are examples of computers that may benefit from having TCP Chimney Offload enabled. To determine if TCP Chimney Offload will benefit an application, run the application with TCP Chimney Offload disabled to establish a performance baseline. While the application runs, capture CPU utilization for each CPU and the network throughput. After you establish the baseline, set the operating system mode of TCP Chimney Offload to either automatic or enabled, as appropriate, and then compare the CPU utilizations and network throughput. Networking Deployment Guide: Deploying High-speed Networking Features http://download.microsoft.com/download/8/E/D/8EDE21BC-0E3B-4E14-AAEA-9E2B03917A09/HSN_Deployment_Guide.doc Performance Tuning Guidelines for Windows Server 2008 R2 http://www.microsoft.com/whdc/system/sysperf/Perf_tun_srv-R2.mspx Regards, Tiger Li TechNet Subscriber Support in forum If you have any feedback on our support, please contact tnmff@microsoft.com.Tiger Li TechNet Community Support

Hi Maurice, Please feel free to let us know if the information was helpful to you. Regards, Tiger Li TechNet Subscriber Support in forum If you have any feedback on our support, please contact tnmff@microsoft.com.Tiger Li TechNet Community Support

Tiger, thanks for reading and posting. You wrote: "After that please verify if the CPU load is quite heavy due to the network transfer. Otherwise, Id rather leave it to disable." How would you check this? Are there any Performance Counters are used to determine if the CPU load is heavy due to network transfer and not other processing activities? /Maurice