I have an old PC. The configuration of the PC is Intel Pentium IV 3.0 GHz, Intel 915GEV motherboard and 1 GB DDR2 533MHz RAM. It has 3 PCI 1.0 regular and one express PCI 1.0 x16 slots.
Can I add any Graphics card having the HDMI O/P port? I got a 3D LED monitor and some of the features of the monitor are not working when the PC is connected. Especially 3D rendering was not at all possible. But when I connected a dell laptop the graphics including the 3D movies played much better.
You aren't going to go anywhere today with 1GB RAM. Instead of putting a GPU in your ancient system, you might want to use that ~$80 to get started on a new CPU+motherboard+4GB RAM. If you go with AMD's A6 APU, you can put something together for around $160. If you want to stick with Intel, you might need to spend closer to $200.