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Title: Advice choosing a PSU ? Only drawing 550w MAX ?? Post by: bilabonic on January 03, 2014, 05:27:16 PM Hi All
I have an MSI Mb and x2 280x cards and it's only using a 550w max . I am not concerned about the efficiency as i have free electric in work ;D The biggest factor is price. Is there a formula or % to add to the 550w being used ?? Or do you subtract a figure from the PSU rating ?? I am also based in the UK Thanks Title: Re: Advice choosing a PSU ? Only drawing 550w MAX ?? Post by: pletharoe on January 04, 2014, 05:11:38 AM How did you come to the 550W figure? According to https://www.asus.com/Graphics_Cards/MATRIXR9280XP3GD5/#specifications each card needs 300W.
Then you also need to factor in the power used by the rest of the machine. Then add a factor of say 20% to accommodate spikes in power draw. I'd look at something with 700 - 800 watts and 80plus certification. Stick to the big brands. Wattage isn't actually the best measure... taken from http://www.extreme.outervision.com/PSUEngine The recommended total Power Supply Wattage gives you a general idea on what to look for BUT it is NOT a crucial factor in power supply selection! Total Amperage Available on the +12V Rail(s) is the most important, followed by the +5V amperage and then the +3.3V amperage Title: Re: Advice choosing a PSU ? Only drawing 550w MAX ?? Post by: bilabonic on January 04, 2014, 08:14:54 AM How did you come to the 550W figure? According to https://www.asus.com/Graphics_Cards/MATRIXR9280XP3GD5/#specifications each card needs 300W. Then you also need to factor in the power used by the rest of the machine. Then add a factor of say 20% to accommodate spikes in power draw. I'd look at something with 700 - 800 watts and 80plus certification. Stick to the big brands. Wattage isn't actually the best measure... taken from http://www.extreme.outervision.com/PSUEngine The recommended total Power Supply Wattage gives you a general idea on what to look for BUT it is NOT a crucial factor in power supply selection! Total Amperage Available on the +12V Rail(s) is the most important, followed by the +5V amperage and then the +3.3V amperage Thanks for reply. I'm using a kill-a-wattmeter, the MAX it has used is 550w inc MB. I just want to run 2 cards off the MB/PSU. So add 20% to 550w = 660w, so a 700/750w 80plus will be ok. Think i will get this - http://www.dabs.com/products/coolermaster-700w-g-series-g700w-80--bronze-power-supply-8Z2S.html?refs=394900000&src=3 |