This is a legacy list, based on the PSU Tier List 2.0. It will rarely be updated. It is meant to be used as a ranking for legacy units only.   All information below is opinion based on fact. Units may be bumped down due to the following: missing protections, group regulation, bad electrical performance and exploding. List is subject to change at any time, due to change in sources available. Sleeve bearing fans will not be placed above Tier 3, and when bumped are marked with 3