If you're looking for general "power" rankings among video cards, you may want to review the lists at
www.videocardbenchmark.net, which may help you pick something relatively equivalent to the card you have.
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While I would never pick an Nvidia card for use with OpenBSD, I just bought one for my daughter, who is beginning art school at the end of this month. She requires a video card capable of computing 3D ray tracing functions within Adobe After Effects, so I acquired a workstation built around one of the few video cards that were both on Adobe's certification list and available.