Upgrading to OS X 10.9 (Mavericks) NOT recommended due to broken CUDA support http://www.primegrid.com/forum_thread.php?id=5340#70479 > If you are currently running any BOINC CUDA projects (not just PrimeGrid) on an Nvidia GPU we recommend that you do NOT UPGRADE to OS X 10.9 (Mavericks) at this time. > According to the BOINC Wiki, the Nvidia CUDA driver is broken. After ugrading to OS X 10.9, you will likely be unable to run any BOINC CUDA tasks until Nvidia fixes the driver.
Release Notes for BOINC 7.0 http://boinc.berkeley.edu/wiki/Release_Notes#Nvidia_CUDA_support_broken_on_OS_X_10.9_.28Mavericks.29 > Nvidia CUDA support broken on OS X 10.9 (Mavericks) > Depending on your Nvidia GPU, the CUDA drivers on Mavericks may not support it. > This is due to Apple changing some things in the drivers for these models. > Nvidia note this in their developer notes, and say it will be fixed soon. > Despite their CUDA v5.5.28 drivers stating they support Mavericks, they actually do not.