OK, here's the answer.
I have an older Intel Core i-7-4790 running at 4 GHz.
My single-core score in Geekbench 4 is 3970.
My single-core score in Geekbench 5 is 830.
Totally different scales!
Assuming things are linear, since the tests appear to be the same, then the new minimum score for Geekbench 5 would appear to be somewhere around 300 - 320.
Thanks, Matt! Those differences between the two scores are ridiculous. Is there a benchmark chart for Geekbench 4? I couldn't find any. Also, did you see what it says in the explanation at the top of the Benchmark Chart for Geekbench 5? Check this out:
"Geekbench 5 scores are calibrated against a baseline score of 1000 (which is the score of an Intel Core i3-8100)"
I scrolled down the chart and found an i7-4790s at 3.2 GHz with a score of 929, which is comparable to yours. I also found my Quad Core Q9650 at 3 GHz with a score of 429, which is above the minimum of 300-320 that you mentioned. So, this seems to explain why I have decent performance for BiaB with my system. Now I'm curious what Angelomusic's Geekbench 5 score would be.