The A4-core bonus was a 10% bonus started in mid 2012 as a temporary bonus to incentivize Folding@home donors to upgrade their clients to version 6.34 and above, allowing scientists using FAH to be able to research larger and more complex biological problems. This has been very successful allowing us to computationally investigate much larger systems including enzymes involved in cancers and vision (see recent blog posts and published work on the Src Kinase, protein kinase C, Rhodopsin, and many others).
While the A4 bonus was designed to be temporary, it has been in place for multiple years, considerably longer than its expected lifetime of three months. We believe it is now time to retire the A4 bonus. Therefore starting March 2, 2015, A4 core based projects will no longer receive both the 10% bonus and the quick return bonus. (They will continue to receive the quick return bonus like most other projects.)
The change should be seamless but please be aware that starting March 2, 2015, returning A4-core work units will see an approximate 10% drop in credited points.