Directly from Elmor:
C6H beta UEFI 1403
* Fixed W_PUMP and AIO_PUMP speeds during POST
* Fixed Fan tuning sometimes failing
* Fixed a few issues with AMD USB3.1 ports
* Some tuning on DRAM settings, let us know how they work for you. tRDRD_Sc is still at 5 above 3500 MHz as it helps with stability. For performance you want to force this to 1. We'll consider changing this in future releases as the performance impact can be quite noticeable in certain applications.
An update on DRAM Boot Voltage, currently it should be 1.35V by default if the DRAM Voltage is changed. So if you're setting DRAM Voltage to above 1.35V, you might want to sync this setting. Additionally there might be scenarios where you will have better luck by syncing DRAM Boot Voltage to DRAM Voltage even at lower values.
Original post and download on Asus' website: Crosshair VI Hero: UEFI build 1403