Symmetrical and Asymmetrical Compute Units - 2021.2 English

Vitis Unified Software Platform Documentation: Application Acceleration Development (UG1393)

Document ID
UG1393
Release Date
2022-03-29
Version
2021.2 English

As discussed in Creating Multiple Instances of a Kernel, multiple compute units (CUs) of a single kernel can be instantiated on the FPGA during the kernel linking process. CUs can be considered symmetrical or asymmetrical with regard to other CUs of the same kernel.

Symmetrical
CUs are considered symmetrical when they have exactly the same connectivity.sp options, and therefore have identical connections to global memory. As a result, the Xilinx Runtime can use them interchangeably. A call to clEnqueueTask can result in the invocation of any instance in a group of symmetrical CUs.
Asymmetrical
CUs are considered asymmetrical when they do not have exactly the same connectivity.sp options, and therefore do not have identical connections to global memory. Using the same setup of input and output buffers, it is not possible for XRT to execute asymmetrical CUs interchangeably.