Can a Dell U2414H work with a mac Pro 3.1 (10.9.5)?

[joelfriedman]

Hi,

Here's my dilemma. I recently bought a Dell U2414 as a 2nd monitor to replace my ancient Dell 2407FWP that died with the understanding that it would work (via a DVI-to-mini displayport cable). It obviously does not. I cannot get a straight answer from Dell if it will ever work. My hunch is the graphics card simply can't handle this monitory.
FYI: I also have an older DELL G2210 (Resolution: 1680 x 1050 @ 60 Hz) on the other DVI port.

Here is the Current Video card info:
ATI Radeon HD 2600 XT: VRAM (Total): 256 MB
Here is my Mac info (on 10.9.5):
Model Name: Mac Pro (early 2008)
Model Identifier: MacPro3,1
Processor Name: Quad-Core Intel Xeon
Processor Speed: 2.8 GHz
16 GB RAM

So my choice seems to be:

1. return the monitor and try to find another 24" that will work with the original card (What is currently still being made that would work with such an old graphics card?)
2. upgrade the card so it can handle the new monitor but still run the old one.

I chatted with OWC about this and they suggested 2 possible upgrade cards but they are not returnable and they could not guarantee they would work with this monitory. It's a risk.

Dell was pretty useless (I person told me yes, the other no).

Here are OWC's suggestions (see below). Can anyone comment and tell me if either will definitively work or suggest another solution? I'd really appreciate it!
ATI Radeon HD 4870
https://eshop.macsales.com/item/Apple/MB999ZMA/
Or more likely: ATI Radeon HD 5870
https://eshop.macsales.com/item/Apple/MC743ZMA/

Best,

Joel