# UART bitrate/speed **URL:** \ **Category:** Jetson Xavier NX\ **Tags:** uart\ **Created:** [April 18, 2021, 1:22pm UTC](https://forums.developer.nvidia.com/t/uart-bitrate-speed/175570 "2021-04-18T13:22:37Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![Andrey1984](https://sea2.discourse-cdn.com/nvidia/user_avatar/forums.developer.nvidia.com/andrey1984/32/14130_2.png) [@Andrey1984](https://forums.developer.nvidia.com/u/Andrey1984)\ **Post date:** [April 18, 2021, 1:22pm UTC](https://forums.developer.nvidia.com/t/uart-bitrate-speed/175570/1 "2021-04-18T13:22:37Z")
```auto baud 115200 means 115200 bits per second only if each baud = 1 bit. If each baud is 5 bits, then having baud 115200 means a bit rate of 115200 * 5 bits per seconds. ``` source [uart - Baud rate vs. Bit rate - Electrical Engineering Stack Exchange](https://electronics.stackexchange.com/questions/214303/baud-rate-vs-bit-rate#) I am trying to find out what bitrate is supported by NX UART It seems that folks with TX2 got it more like 8Mbit/S, right? So will it be the highest possible bitrate for the NX devkit? Or even 1Mbit/S is problematic? > [@High Baud Rate UART Configuration](https://forums.developer.nvidia.com/t/high-baud-rate-uart-configuration/79392/2): > > hello oliver30sgx, according to TX2 TRM, the maximum baud rate is 12.5Mbps. please also access [Tegra X2 (Parker Series SoC) Technical Reference Manual](https://developer.nvidia.com/embedded/downloads#), and check the [UNIVERSAL ASYNCHRONOUS RECEIVER/TRANSMITTER (UART)] chapter. please also refer to [Jetson TX2 Series Software Features](https://docs.nvidia.com/jetson/archives/l4t-archived/l4t-322/index.html#page/Tegra%2520Linux%2520Driver%2520Package%2520Development%2520Guide%2Fsoftware_features_tx2_tx2i.html%23wwpID0E0NB0HA) for the uart speeds. you could also refer to UART registers in the Technical Reference Manual thanks ---
**Author:** ![linuxdev](https://sea2.discourse-cdn.com/nvidia/user_avatar/forums.developer.nvidia.com/linuxdev/32/10243_2.png) [@linuxdev](https://forums.developer.nvidia.com/u/linuxdev)\ **Post date:** [April 18, 2021, 7:15pm UTC](https://forums.developer.nvidia.com/t/uart-bitrate-speed/175570/2 "2021-04-18T19:15:18Z")
I have not done so personally, but I know people have: A. Succeeded at this rate. B. Not had this be useful unless using two stop bits (because the clock is not in spec). Does the other end of the UART connection have the ability to use two stop bits? If it does, then I think you will succeed, but if not, then I think you will be frustrated even if you get that rate. ---
**Author:** ![DaneLLL](https://sea2.discourse-cdn.com/nvidia/user_avatar/forums.developer.nvidia.com/danelll/32/14043_2.png) [@DaneLLL](https://forums.developer.nvidia.com/u/DaneLLL)\ **Post date:** [April 19, 2021, 4:50am UTC](https://forums.developer.nvidia.com/t/uart-bitrate-speed/175570/4 "2021-04-19T04:50:29Z")
Hi, Per Xavier TRM, maximum baud rate is 12.5MHz and identical to TX2. There is a post about running at 12Mbps. Please refer to [Jetson AGX Xavier UARt at Higher Baudrate - #3 by JerryChang](https://forums.developer.nvidia.com/t/jetson-agx-xavier-uart-at-higher-baudrate/159063/3) ---
**Author:** ![Andrey1984](https://sea2.discourse-cdn.com/nvidia/user_avatar/forums.developer.nvidia.com/andrey1984/32/14130_2.png) [@Andrey1984](https://forums.developer.nvidia.com/u/Andrey1984)\ **Post date:** [April 19, 2021, 8:19am UTC](https://forums.developer.nvidia.com/t/uart-bitrate-speed/175570/5 "2021-04-19T08:19:06Z")
@DaneLLL Thank you for following up! Can we use something similar to iperf to monitor the bandwidth capacity of UART ? ---
**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:** [May 5, 2021, 1:15am UTC](https://forums.developer.nvidia.com/t/uart-bitrate-speed/175570/9 "2021-05-05T01:15:06Z")
> [@Andrey1984](#): > > Can we use something similar to iperf to monitor the bandwidth capacity of UART ? Sounds a good idea, but we don’t have tool, and need to to investigate. Sorry for that. ---
**Author:** ![linuxdev](https://sea2.discourse-cdn.com/nvidia/user_avatar/forums.developer.nvidia.com/linuxdev/32/10243_2.png) [@linuxdev](https://forums.developer.nvidia.com/u/linuxdev)\ **Post date:** [May 5, 2021, 5:33pm UTC](https://forums.developer.nvidia.com/t/uart-bitrate-speed/175570/10 "2021-05-05T17:33:49Z")
I suppose there might be some weird way to use `netcat` with `iperf`, and then the `netcat` destination is just localhost, whereby the destination is what talks to the UART (via another pipe). Loopback networking would be a bit of a penalty, but it would be trivial in comparison to UART speeds (the trick being you’d have to force ethernet to send immediately instead of waiting for MTU or delaying and sending on timeout if MTU is not reached). ---
**Author:** ![nadeemm](https://sea2.discourse-cdn.com/nvidia/user_avatar/forums.developer.nvidia.com/nadeemm/32/367020_2.png) [@nadeemm](https://forums.developer.nvidia.com/u/nadeemm)\ **Post date:** [October 18, 2021, 6:41pm UTC](https://forums.developer.nvidia.com/t/uart-bitrate-speed/175570/12 "2021-10-18T18:41:24Z")