You would definitely notice such a slowdown when working on your PC. (tomsguide.com)
But is such a slowdown already underway today? (realclimate.org)
To find out how severe such slowdowns might be, Mike Lockwood and Matt Owens at the University of Reading, UK, used the 2008 measurements to model the belt's thickness during the most extreme solar minimum on record: the Maunder Minimum. (newscientist.com)