On 08/05/18 10:50 AM, Christian König wrote: > E.g. transactions are initially send to the root complex for > translation, that's for sure. But at least for AMD GPUs the root complex > answers with the translated address which is then cached in the device. > > So further transactions for the same address range then go directly to > the destination. Sounds like you are referring to Address Translation Services (ATS). This is quite separate from ACS and, to my knowledge, isn't widely supported by switch hardware. Logan