Upgrade graphics card for Z97Pro4

I have Z97Pro4's with an old GeForce GTS 450 graphics card. I'm wanting advice about a new graphics card. I'm not a gamer.

Here's my Z97Pro4's components:

BIOS: version 6/12/2015
Processor: i7-4790K 4.1 - 4.4 GHz, cores, 8MB Cache (Model: BX80646I74790K)
CPU Cooling: Intel Heatsink Fan Thermal Controlled
Memory: Corsair Vengeance Pro Series 16GB (2 x 8GB) DDR3-2400MHz C11, 1.65v
Power Supply: Ultra 600 3X ULT40073
PCX Video: nVidia GeForce GTS 450, PCI-Express 2.0, dual Monitor DVI, DVI, Mini-HDMI, Wireless Type: 802.11bgn
Three monitors: 30??Dell and two 19" ACER monitors
Samsung SSD 970 Plus, 500GB, M.2 NVMe C:
Samsung SSD 850 Pro, 256GB D:
OCZ Vertex 256GB
SSD: Samsung Portable SSD T5
Router: TRENDnet?™s AC1900 Dual Band Wireless Router, model TEW-818DRU
Windows 10 Pro X64
Modem: SMC Networks D3CM1604 Modem (DOCSIS 3.0, 16x4 Channel Bonding) Approved for Time Warner Cable, Charter, Cox, Spectrum
Road Runner 200 MB High Speed

The Dell has a DVI-D port, the Acers have HDMI ports. I plan to eventually upgrade to a 4K monitor.

Thanks, Kerry

What do you use the system for? You may not be a gamer but if you do video rendering
a better GPU could be helpful (Nvidia's CUDA acceleration). If you use photoshop
you may want something with high 2d performance that will improve scrolling etc.

Your board will support any PCIe GPU that is an upgrade from your GTS 450 so if
that was your concern you have nothing to worry about on that front.

From a value prospect I would suggest an RX 570 4gb, it will have the display
outputs you need and should be more than quick enough for any non gaming task.
Just be sure you don't get a card that was designed for mining (it will be
described as such) that only has a single display output. Mining and used mining
cards are good value but often lack display outputs and have cooling solutions
that are built for pushing high airflow rather than silence.

If you are using a lot of software that benefits from GPU acceleration you should
find out what GPU acceleration they use, AMD's direct compute or Nvidia's CUDA
acceleration. That will decide which vendor to go for.

If all you want is decent video playback and multi display support then the RX
570 is the way to go. Anything cheaper at this point is poor value considering
how cheap the 570 is right now. It will also last you longer than a budget GPU.