These are the speedtest results on my three machines using the vesa driver and the 16 color videomode:
Vodoo 3 Intel740 S3 640x480 crash ok ok 800*600 crash not available ok 1024*768 not available not available ok
The crash with the Vodoo 3 is total, I need to reboot, even using ::R. But all other tests work ok (and other videmodes too).
The crash come in the drawhlinetest function (but some times in the drawlinetest). I had tried to use GrHLine instead GrHLineNC, but it crash again.