It must be the same as maximum USB rate, as there is no faster input.
Problem you experience is with USB maximum rate. For PCM it is 384khz. DSD is difficult to understand, as there are two transfer methods: DoP and native.
What is your source (device/OS/player)? Your action depends on this.
DoP is supported by any OS, it is encapsulating DSD datastream in PCM frames which translate DSD64 to 176.4kHz and DSD128 to 352.8kHz. As you see, it is already approaching maximum PCM rate. It is why you can't get any further.
For a higher rate than DSD128 you need to force a native DSD transfer over USB which is not supported by Windows. Only few players support native transfers, they will use ASIO interface which is available after installing Amanero drivers.
Check such capability to transfer native DSD with your player. There is also Amanero firmware optimised for Linux, it require to install different drivers when working with Windows. Default firmware is optimised for Windows.