New Radeon Card but Possible PSU Issue

[Erebor]

Hi, I have just moved from a Radeon HD6950 to a Radeon RX 460 and graphics are not as smooth, especially when I am also running videos from my browser while playing. I'm not all that pc literate, but I have the sense that maybe there is not enough power to run everything. I did have only one cable from PSU to card for the RX460, while I ran two on the old card. Does it matter than I have one cable not being used, is the other one getting all the juice if its brother is not plugged in to anything? The old card ran everything just great, but appears that new cards may must need more power.
I'm on Windows 7 on an Asus M5a97 motherboard.

 

[dontlistentome]

You have it backwards, new cards use less power. Over time, designs become more efficient, the cards don't need that much power like the old days. I think your problem may be that in some uses, the 6950 is more powerful than the RX 460. The 460 is an entry level card of its generation, the low end. The 6950 was a very fast card in its generation, a top end card. However, this is in gaming. Videos should run fine on the 460, so I'm wondering if you uninstalled the old videocard drivers and installed the new ones correctly.

 

[Erebor]

I did uninstall old driver and installed new one from website. I did not install the accompanying software suite. I'm detecting problems when running a demanding game with intense graphics. Based on your response, I could go up a model or two on the graphics card and not worry about the PSU issue, or about going to just one cable from PSU to card.