What is the difference between gold and bronze PSU? Can one be quieter than the other? - Quora
Amazon.com: Zalman GigaMax 600W 80+ Bronze Power Supply, High Efficiency Stable Output, 5 Year Warranty, Certified 80 Plus PSU, Up to 87% Efficiency, Non-Modular (600 Watts) : Electronics
Extreme 500 Bronze
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Cooler Master MasterWatt 550W 80 Plus Bronze Power Supply (US Plug) for sale online | eBay
PC power supply ratings: 80 Plus Platinum vs Gold vs Bronze vs White | PCWorld