Cheap PCI 2.0 and 4K

[this_1]

I'm looking to upgrade my GTX 560 (2GB) to a GPU which can display 4K (video and desktop). I'd likely use a lower resolution for occasional gaming.

My Gigabyte GA-Z68A-D3-B3 supports PCIe 2.0 x16.

Requirements:
- Compatible with my motherboard
- Can display 4K video
- Minimize price
- Discontinued GPUs okay

 

[Darkseiders]

An R9 390x or GTX 980 would be fine. GPUs are backwards compatible with PCIe 2.0 x16.

 

[cst1992]

Any card which is the 900 series is fine for 4K video at 60Hz. Look for HDMI 2.0 support.
Any card which is GT 740 or higher is fine for basic 4K output at 24Hz over HDMI.
Any card with DisplayPort outputs is fine for 4K at 60Hz frequency.

The PCI-E bus doesn't matter. All cards are compatible with even PCI-E 1.1, and frankly it doesn't come into play here at all. It's for communication between the processor and graphics card.