Etasis 850W Power Supply

So I just picked up this power supply brand new in the box for $9.99. I am wondering what video cards I can power with it. I am powering my r9 290 at the moment with my XFX 550w. Could this do any crazy power hungry crossfire configs? Like two r9 390x or maybe even fury X in crossfire. What will be the limit on this power supply?

It has Japanese caps it looks like too. It has a 4 rail design at 18A each, and was built in 2007 or 2006.

850W should be enough for crossfire.

I'm worried about not providing enough power. Being an older power supply I would assume it can't push out the same amps as the new ones.

You can likely use two power hungry GPUs in such a configuration with a CPU that pulls a decent amount of power too.
If the supply is brand new out of the box it wont have degraded, shelf life is very long on such components.

Seems like the brand doesn't underspecc their parts either, so the PSU can likely handle more than 850w if you're using 230v mains.

So I can do two fury X + i7 2600 + a lot of hard drives? Awesome!
I am on 120v.

You can totally do that, not that you would want to do that though.

Yeah it would be a waste of money. I just want to know ahead of time in case I do decide to power something crazy.