Quote from OldTrader:
Power supply is 525W, should be more than adequate for what I'm running. Those enclosures are about 1/4"x1/4"x1/4", with an opening you can see copper through. There's two of them on the back of the card. I don't really see anything that looks like a fan though. So maybe the CPU fan kicks on immediately for some reason. That said, there's no fan at all with the 290 card, so this 440 card must be related to the fan action in some way.
OldTrader
The fan assembly, if there were one, would cover 1/2 or more of the entire card.
If you still want to try a 440, suggest you exchange your x1 for an x16. Must be some sort of hardware conflict with that x1.
The 440 is rated for only 31 watts, so power requirements normally wouldn't be an issue, regardless.