It kind of makes sense tho.

Some people were making CGI for movies on SGI boxes.

And naturally, some of the movies where SGI machines were involved ended up putting those machines in the movie itself:

> Jurassic Park featured a lot of computer generated images and it was one of the first movies to show SGI computers on screen.

http://www.sgistuff.net/funstuff/hollywood/jpark.html

http://www.sgistuff.net/funstuff/hollywood/index.html

So if the SGI computers made a lot of computer noises. Perhaps this helped inspire the portrayal of noisy computers in hacker movies.