According to the Intel X550 datasheet (1), the controller supports IEEE 802.3az Energy Efficient Ethernet (EEE). It's also added as a key feature on the Intel's X550 Product Brief (2). However, it seems that 802.3az support has been silently dropped from the Intel X550-T1/T2 product brief (2) even if a product guide from Lenovo clearly mark this feature as supported. This feature is important for EE datacenters, especially for power-hungry 10GBase-T connectivity. We tried to get EEE working on X550-T1/T2 CNA on various switches without success. It seems this features is disabled or broken. PROSet 21.1 does not include any settings related to EEE.
Can you please give us the current status of 802.3az (EEE) on Intel's X550-T1/T2 CNA?
PS : Additionally, do you have an ETA for NBase-T support on these NICs? According to the product brief, this feature is marked as "to be enabled in a post-launch firmware release".
(1) http://www.intel.com/content/dam/www/public/us/en/documents/datasheets/ethernet-x550-datasheet.pdf
(3) http://www.intel.com/content/dam/www/public/us/en/documents/product-briefs/ethernet-x550-brief.pdf