# Jetson Thor MGBE XFI signals to support 100M/1G link speed **URL:** \ **Category:** Jetson Thor\ **Tags:** mgbe\ **Created:** [September 28, 2025, 7:13am UTC](https://forums.developer.nvidia.com/t/jetson-thor-mgbe-xfi-signals-to-support-100m-1g-link-speed/346240 "2025-09-28T07:13:29Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![xus](https://developer.download.nvidia.com/images/forums/profile-default-devtalk-84.png) [@xus](https://forums.developer.nvidia.com/u/xus)\ **Post date:** [September 28, 2025, 7:13am UTC](https://forums.developer.nvidia.com/t/jetson-thor-mgbe-xfi-signals-to-support-100m-1g-link-speed/346240/1 "2025-09-28T07:13:29Z")
From the source code of the mgbe controller driver in drivers/net/ethernet/nvidia/nvethernet/ether\_linux.c, it is understood that in the USXGMII 10G PHY interface mode, the PHY line side only supports link rates of 10G/5G/2.5G. The PHY in XFI mode we are using only supports link rates of 2.5G/5G, whereas in the USXGMII mode can support link rates of 100M/1G/2.5G/5G. How should this PHY be configured to enable the XFI data line to support 100M and 1G link rates? ![usxgmii](https://global.discourse-cdn.com/nvidia/original/4X/7/d/1/7d14eb6284d21c804f08d7c378ed9d6966c27927.png) ---
**Author:** ![kayccc](https://sea2.discourse-cdn.com/nvidia/user_avatar/forums.developer.nvidia.com/kayccc/32/14043_2.png) [@kayccc](https://forums.developer.nvidia.com/u/kayccc)\ **Post date:** [October 8, 2025, 7:27am UTC](https://forums.developer.nvidia.com/t/jetson-thor-mgbe-xfi-signals-to-support-100m-1g-link-speed/346240/4 "2025-10-08T07:27:39Z")
We’re investigating if able to support. ---
**Author:** ![WayneWWW](https://sea2.discourse-cdn.com/nvidia/user_avatar/forums.developer.nvidia.com/waynewww/32/14043_2.png) [@WayneWWW](https://forums.developer.nvidia.com/u/WayneWWW)\ **Post date:** [October 8, 2025, 8:00am UTC](https://forums.developer.nvidia.com/t/jetson-thor-mgbe-xfi-signals-to-support-100m-1g-link-speed/346240/5 "2025-10-08T08:00:38Z")
No, we don’t support XFI/MDIO/PHY connection on Thor MGBE. Only QSFP is supported. ---
**Author:** ![xus](https://developer.download.nvidia.com/images/forums/profile-default-devtalk-84.png) [@xus](https://forums.developer.nvidia.com/u/xus)\ **Post date:** [October 9, 2025, 1:52am UTC](https://forums.developer.nvidia.com/t/jetson-thor-mgbe-xfi-signals-to-support-100m-1g-link-speed/346240/7 "2025-10-09T01:52:27Z")
Thanks for reply. The attached image illustrates the PHY’s support for various rates in SFI and USXGMII modes. As we have verified that the communication operates normally at 2.5Gbps. How should the MAC side be configured to ensure that the PHY linked at 100Mbps/1Gbps can establish normal communication with the MAC? ![speed table](https://global.discourse-cdn.com/nvidia/original/4X/8/7/3/873a8b032ea4f814d976650dae23674d751c5009.png) ---
**Author:** ![WayneWWW](https://sea2.discourse-cdn.com/nvidia/user_avatar/forums.developer.nvidia.com/waynewww/32/14043_2.png) [@WayneWWW](https://forums.developer.nvidia.com/u/WayneWWW)\ **Post date:** [October 9, 2025, 3:16am UTC](https://forums.developer.nvidia.com/t/jetson-thor-mgbe-xfi-signals-to-support-100m-1g-link-speed/346240/8 "2025-10-09T03:16:10Z")
Not sure what does this question mean here as my point previously was we don’t support Ethernet PHY but only QSFP modules. ---
**Author:** ![system](https://sea2.discourse-cdn.com/nvidia/user_avatar/forums.developer.nvidia.com/system/32/68080_2.png) [@system](https://forums.developer.nvidia.com/u/system)\ **Post date:** [November 4, 2025, 6:34am UTC](https://forums.developer.nvidia.com/t/jetson-thor-mgbe-xfi-signals-to-support-100m-1g-link-speed/346240/10 "2025-11-04T06:34:07Z")
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