Is my PSU sufficient for new graphic card?

[majk411]

This is what I have:

Intel Core i5-4590 tray 3.3 GHz, turbo boost up to 3.7 GHz
motherboard MSI B85-G41 PC Mate
cooler Arctic Freezer 13 (will be soon replaced by SilentiumPC Spartan LT HE922)
2x 4GB DDR3 RAM 1333 MHz
HDD Western Digital 500GB, 16MB, 7200rpm
PSU Seasonic SS-500ET, 80+ Bronze, 500W
(no CD/DVD ROM

I want to buy new graphic card, im not sure which one to grab though. Originally the plan was to get R9 380 4G from MSI. Then I noticed i could get MSI R9 280X 3G for almost the same price. I did some research and it seems like 280x is the better choice, but it does consume more power. I don't really know hot to calculate this, I have no experience with it. Would my 500W PSU be sufficient for R9 280X 3G? I will be eventually getting some new HDD (at least 1TB 7200rpm).
So, can I run the R9 280x 3G? And if yes, could I run it with additional HDD? Or should I just get R9 380 4G?

 

[davidarad02]

it would be sufficient, but I recommend getting the 380, because the extra 1GB of ram will help you in the future, and with some games, even today. im running a GTX 970 (with "has" 4 GB of ram, and without maxing GTAV (but still almost maxed) and im hitting 3.5GB, so think how VRAM intensive future games will be...

 

[majk411]

OK, I guess that makes sense. R9 380 4g it is, thank you for your answer.