I can send picture before or after sale of the exact card you will receive.
There is also full boot screen support from the DVI port (Shows the Apple logo at startup - Useful switching boot drives and bootcamp). Early 2008 Apple Mac Pro nVidia Geforce 8800GT 512MB Video Graphics Card. You will receive a similar AMD 5870 1GB reference design model with the 2 DVI PORTS, 1 HDMI, 1 STANDARD DISPLAY PORT and 2 6 pin power connections as shown in picture. Supported display configurations Mac Pro supports the following display configurations, depending on the graphics cards installed.
These are serious cards and are great for 4K video work! They also have the full 5.0GT/s link speed! If a Radeon Pro MPX Module isn't installed, the Thunderbolt 3 ports on your Mac Pro are used only for data and power. Cooler 3GB GDDR5 384bit Dual-Link DVI-I DVI-D HDMI DP SLI Graphics Cards 03G-P4-2884-KR. Pro Tools Ultimate 2021.12 HDX, UA Octo PCIe card in external TB3 chassis, MTRX Studio I/O, C24 control surface. It supports Hyper-Threading which allows two threads to run simultaneously on each core - so macOS will recognize up to 24 total cores, 12 real and 12 virtual. The Mac Pro can be configured with single or dual 64-bit Intel Xeon Westmere 6-core processors. These cards are also compatible with Apple's own Metal 2 API AMD - Ryzen 7 1700X 3.4GHz 8-Core Processor Mac Pro, Budgeting. Mac Pro 5,1 3.46 Ghz 12 core, Open Core 0.7.6 EFI, Radeon RX580 GPU, GC-TITAN RIDGE TB3 PCIe card, M.2 NVMe SSD boot drive on PCIe card, 48GB RAM, macOS 11.6.5. 2010-2013 Apple Mac Pro Tower - Model 5,1. You can run multiple 4K displays from this card!
It is possible in theory to fit a standard PCIe video card in a PCIe expansion box and connect that expansion box via Thunderbolt to a computer which of course supports Thunderbolt, e.g. Store > Recommended: Mac Pro 4,1 and 5,1 > Apple EFI AMD RX580 4GB and 8GB Sapphire Pulse for Mac Pro 4,1/5,1 Apple EFI AMD RX580 4GB and 8GB Sapphire Pulse for Mac Pro 4,1/5,1 SKU: 689.00. Here for sale is an AMD Radeon RX580 8GB VRAM Graphics Video Card For Apple Mac Pro 4K 2009-2012 flashed with the latest firmware and is compatible in all models of Mac Pro from 2009-2012 (models 4,1 & 5,1) Detailed spec for the card can be found below but i will say that this has a Dual Link DVI, Dual HDMI and Dual Display Port outputs. As Illaass said you cannot add Thunderbolt to a classic Mac Pro i.e.