Information giving so far suggests that you are running Vivado on your local computer. So we can expect that your working directory is also local, otherwise there could be an additional performance problem.
I'm not familiar with Xilinx tools, presume they are using multiple processor cores to some extend. It's surely documented, the CPU utilization should be also listed in report files. To decide if multiple parallel compilation on multiple tool instances can potentially speed up anything, you have the information at your finger tips. I'm however not sure if your tool license allows it.
Nothing has been yet said about the design nature, I guess combinational loops are not the dominant problem.