Unfortunately you will need to upgrade everything except the PS. I am not up to speed on your case but all new mother boards require ddr4 memory and your video card is about the minimum for MadVR. You also want a PCI SSD as they are 4 times faster then SATA. Just as an example I just upgraded mine to a Ryzen 7 2700 (last years cpu as the 3700 is just been released), new Biostar AM4 motherboard, 16GB of DDR4 3200 mem, and a 256GB PCIe SSD all for well under $300.
"Smart enough to know better, to old to care" ------ Dedicated Bat Cave Home Theater, JVC RS49U/Mitsubishi HC7900DW Projector, 110" 16:9 Jamestown screen with variable power masking for CIW 2.50:1 to 16:9, Marantz 7009 with 7.1.4 Atmos with Ohm mains,3 DIY Subs (2 15" (1 ported, 1 sealed and a 12" 4th order bandpass), 1 DIY butt kicker, Custom Built HTPC, 18TB DroboFS NAS