https://www.asus.com/us/SupportOnly/A8R-MVP/HelpDesk_Manual/
https://dlcdnets.asus.com/pub/ASUS/mb/socket939/A8R-MVP/e2319_a8r-mvp.pdf
see page 2-3 for mobo layout, it has a total of 6 PCI slots... 2 PCIE and 3 PCI (not PCIE) and one pciex1.
the second slot down from the top most slot is PCIE X16_1. The top one being PCIE X16_2
. It has two x16 pcie slots.
page 2-16
This motherboard supports two ATI CrossFire™ PCI Express x16 graphics cards that comply with the PCI Express specifications. The figure shows two graphics cards installed on the PCI Express x16 slots.
so not too shabby for an old board. Would it support two Nvidia cards, I don't know. But it would support any one PCIE type graphics card either nvidia or ATI/AMD.
I did not find if it supports PCIE 1.0 or 2.0 or 3.0, but in any case any late model PCIE graphics card that is PCIE 3.0 or 4.0 will work. From there it is a matter of if your Power Supply supplies supplemental pcie 6-pin or 8-pin power to the graphics card for whether or not you could get a high end double width type video card like an nvidia RTX3060.
see https://videocardbenchmarks.net and https://pcmecca.com/best-low-power-graphics-cards-without-external-power/
https://www.gpumag.com/gpu-power-connectors-explained/
https://www.cgdirector.com/gpu-power-cable-guide/
p.s. everything is well except for my ssh problem :)