If I recall your old post had the Make/Model of the PSU.
I did check out the load under stress on Tomshardware.com for the 280x and it seemed OK. But if you were going to replace the PSU we've need to know the current power draw to nail this down.
I use this to measure that -> http://www.amazon.com/gp/product/B00009MDBU/ref=CNET
Bob
Hey everyone so I have a basic gaming rig and want to upgrade my graphics card from a Radeon R7 260x to a Radeon R9 280x. The 280x I'm looking to get requires a 500W power supply. I have a 530W power supply right now so I think I need to upgrade my power supply as well. I use my computer for gaming, recording software, and rendering softwares. What is a good power supply that will allow me to do all these things and upgrade my graphics card? I heard 750W should be enough but I want to know a reliable name brand and ones that give a good price. Top I would pay is about $150. Thanks for the help!

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