Posted 25 December 2015 - 03:13 AM
You can in theory run a card of that nature on a 450 watt PSU providing its a high end PSU and your running little to no other accessories on your system, and even then your cutting it close. If its your computer and you know what your doing then you can probably get by with it, at least for awhile, though your still putting undue stress on it.
Now, recommending to someone else you've only met over the internet that they use a 450 watt PSU without any knowledge of their entire computer setup, is irresponsible at best. If the op purchases such a low wattage PSU on your recommendation and it fries, are you going to buy him a new one? I didn't think so. The manufacturer recommends 500 watt then the op wants to have at least 500 watts. In fact it maybe helpful for him to visit neweggs power supply calculator, but I would say for any good modern gaming computer, 550-600 watts is a good happy medium that will run most single video cards and 8-900 to be on the safe side for crossfire.
Now, as far as video card recommendations, I just ordered the sapphire nitro r9 380 4gb model. I'm running it combined with a AMD phenom II 945 quad core with 16 gigs of ram, so like you I'm running an older system, but the card is performing great on the system and will serve you great as well. It is only midrange but its powerful and directX12 capable which the 7xxx cards are not. This card is running about $220 on newegg right now with a $15 mail in rebate. But, as has been previously stated, you need to upgrade your PSU to a MINIMUM of 500 watts, if not 600, to be safe. Using a power supply calculator will help determine what you actually need. And make sure its a good PSU, not a cheap one, and modular if you can afford them will change your life.
Primary system: Motherboard: ASUS M4A89GTD PRO/USB3, Processor: AMD Phenom II x4 945, Memory: 16 gigs of Patriot G2 DDR3 1600, Video: AMD Sapphire Nitro R9 380, Storage: 1 WD 500 gig HD, 1 Hitachi 500 gig HD, and Power supply: Coolermaster 750 watt, OS: Windows 10 64 bit.
Media Center: Motherboard: Gigabyte mp61p-S3, Processor: AMD Athlon 64 x2 6000+, Memory: 6 gigs Patriot DDR2 800, Video: Gigabyte GeForce GT730, Storage: 500 gig Hitachi, PSU: Seasonic M1211 620W full modular, OS: Windows 10.
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