When you upgrade to a different model of video card, even if it's from the same chipset brand, it's a good idea to reinstall your drivers. Although it might seem like it's working fine 'plug & play', it won't be optimized, and there can be known issues with crashes and driver conflicts. For the best performance and stability, I'd recommend uninstalling the old drivers, swapping out your GPU, and then reinstalling the new drivers. Here's a helpful
link that provides more details on this topic.