My game crashed every time I tried to summon a genie (djinn), so I started over making a playable genie, to make sure it was not the graphics. It was not the graphics.
Started the new game in the downloaded world of Los Aniegos, a huge town preloaded with lots of sims. The game stuttered on the highest resolution, but reducing draw distance and the number of lots rendered in detail gave me a non-distracting speed. That's better than I got on any of the three earlier machines I have played this game on.
The reason why the game crashed when cleaning the dusty old lamp? Mods. After upgrading them to the newest version, the game did not crash, it just cleans the lamp without summoning the genie. After removing the mods, the summoning worked as it should. The culprit turned out to be Awesomemod, strangely enough. Usually it fixes glitches rather than causing them. It is just recently updated too. I would guess that it is my particular combination of installed expansions, rather than the machine, that causes this glitch.