Need help with PSU and my video card

The HD6670 should run fine on a 300w, especially one from Dell. Even if the PSU wasn't sufficient it wouldn't cause the problem you are talking about. Most likely the RAM that is not available is defective. If you bought it recently you can return it. If not it should still be under warranty and you can get it repaired/replaced if you want to. You may just want to keep it though. A card of the caliber of the HD6670 cannot really take advantage of the full 1gb of RAM so it isn't that big of a deal.

In your opinion, do you think I should return it? If so. how would I go about doing that?

does the number move? you say it can go up to 1gb

where are you looking at for the number?

I'd think he is looking at the card's specs. I don't think I've seen any HD6670s that are supposed to have under 1gb of ram.

Sounds like a defect for sure, but what are you checking the video memory with?

If I can run a 5770 on a 300 watt power supply(FSP brand), your 6670(and take less then half the power of a 5770) will be just fine