will this work?

[Bobbysonators]

Can I run a gtx 470 reference on 405w power supply?

 

[CTurbo]

No probably not. I think it's pretty safe to assume that a 405w psu is not very good. Probably no where near 400w.

 

[Karadjgne]

https://www.google.com/url?sa=t&source=web&rct=j&url=http://m.youtube.com/watch%3Fv%3Df6snWfd1v7M&ved=0ahUKEwjW_vGX3qvOAhVHziYKHSMMDeAQtwIIHjAB&usg=AFQjCNEEGvShTGHLwRbILoZOieMJsbP5OA&sig2=VIIB3vv9rsFDOx31E_-udg

Don't be fooled by names or ratings. When it comes to psu's there are plenty that promise and few that actually deliver. A $70, good psu is cheap insurance vrs the $800+ of a decent pc

 

[Bobbysonators]

No probably not. I think it's pretty safe to assume that a 405w psu is not very good. Probably no where near 400w.

I forgot to mention the other parts of my PC (oops) there is 2x 4gb sticks of ddr3 1600 a 7200rpm 500gb hdd and an i3 2100 there is 300w on the 12v rail also.

 

[CTurbo]

You need a new psu.

 

[Karadjgne]

New psu. Recommended wattage for a Rx 470 is @450w. Best cheaper option would be Seasonic S12-II 520w, Antec HCG-M 520w, XFX TS/Pro 550w.

 

[Bobbysonators]

What would I need for a hd 5970

 

[Karadjgne]

For the small HD5970 - 650w
For the 4Gb 900/1200 HD5970 - 750w

Most definitely, beyond any shadow of a doubt, need a new psu.