Need an upgrade from Radeon R7 250

[Zproduction1]

To be honest, I don't know TOO much about computers so I bought a gaming rig to improve as I learn and want more out of it... Is it good? Speed wise, it's bangin. But I know it lacks in graphics

Computer Specs:
Cyberpower PC, Model: GUA3400A
AMD Radeon R7 250, 2GB Graphics RAM
AMD FX-6300, 6-core, 3.5GHz
1TB Sata III
SDRAM DDR3 8GB
Serial ATA-600
HD Rotation speed: 7200 rpm

Is there anything I need to know specifically when looking to improve my graphics card? I know it often requires a new power block, fans, etc. but what else do I look into?

Per example, does it have to be a "PCI-E 3.0x8" or what should I be looking for, for a smooth transition?

*Examples/Links to upgrades would be appreciated as well!*

It's my 1st post, don't let me down! 😛
Thanks!

EDIT: I'm looking for an upgrade to play Fallout 4, SOMA, Skyrim (w. ENB presets) on ultra settings. (I'll take high as well)

 

[radekmm]

you can upgrade to any card you wish as long as your power supply is good enough, but in your case i recommend a r9 380, this will be a very nice bump in performance

 

[naturesninja]

Budget? Current Power supply?

 

[Zproduction1]

Budget? Current Power supply?

It's more of a informative question, just so you know. More so, that I can see and understand my options rather than run out and get it immediately.

- I'd be willing to be spend about $300 on a card
- Current power supply:I do not know. It did not come with, nor suggest a power supply/block. Only the wire from the PC to the outlet that was provided. (If you know how I can determine it otherwise, I'll be happy to check)

 

[naturesninja]

Well I just saw that this was a cyberpower prebuilt. So without upgrading the PSU, the best card you could replace it with would be the GTX 750ti @ $100-130 usually. That won't give you what you seek though. An R9 380 4GB or GTX 960 4GB would be around $200 give or take. About $50-60 for a decent PSU to go along (antec/seasonic 520w/620w, xfx 550, a couple others). Another thing to consider is how much room you have in your case, measure twice, buy once.