Hello
You have the option to make us of the parallelism for few phases during an upgrade.
Check this SAP note understand how it works
1616401 - Understanding parallelism during the Upgrades, EhPs and Support Packages implementations
What matters is the hardware resources. If the hardware has enough CPU and RAM then it will help.
If the logs are getting updated and if the phase is not running in a loop then I would wait.
What is the underlying database you are using ?
Regards
RB