My old 9500 GT is insufficient to be seen by Lightroom and used for GPU acceleration. I don't want to spend much on my old PC so might this card - EVGA GT 710 2GB DDR3 64bit Single Slot, Dual DVI 02G-P3-2717-KR - meet the Lightroom specs?  (I'd include them, but as a new member I apparently can't insert a link yet).  
VRAM - 2GB GPU Ram - 4GB GPU Ram for 4k displays and greater
For best performance, use a discrete graphics card that has the GPU Compute benchmark score of 2000 or greater.