Speed and memory
In our performance index the Radeon HD 6950 scores 3 and the GeForce GT 1030 scores 2.5, which makes the Radeon HD 6950 about 20% faster. That is a visible but modest gap, usually 5 to 10 fps in a game that runs at 60.
Both cards have 2 GB of video memory, so memory will not separate them.
In our estimates for popular games at 1080p on High, the biggest gap is in Call of Duty (5 against 4 fps), and the smallest is in ELDEN RING (8 against 7 fps). Games that are light enough to run above 200 fps on both cards show little difference at all.