Try my old jetscream game (free 3 level playable demo) it was written on a duron 800 XP 128mb and an intel 82815GPU you will need to run setup and turn off all the detail except water reflections.
It will certainly stress your machine but will be 'playable' you can then increse the stress level by increasing resolution/detail etc
www.d-grafix.com
It will certainly stress your machine but will be 'playable' you can then increse the stress level by increasing resolution/detail etc
www.d-grafix.com