If it's a problem of hardware, ask for help from more powered users. Which hardware is using your rendering box ?
If it's not a problem of hardware, try to reduce the number of lights, the level of surface subdvision. For testing purpose, you can try to render with lower AA and lower resolution. What settings do you use at the moment ?
i'm trying to render now tih 5 lights low iradiance map and low AA .. a 640 resolution .. and the est time is 7 hours and rising ... dunno whats the problem :| ... hardware maybe ... i have a capry amd semprons 2400+ which works around 1.6 ... 2 gb DDR1 and an ati sapphire 9550 128 MB ... :|
so ... i was patient enough to try to render at 640 ... lowest details ... as you can see almost 5 hours went and this is the lvl of rendering and another 7 hours remained ... but i've got sick ... here is the pic with waht was doen in those 4 hours
try to reset scene......... try to merge scene with other empty scene. Try to change render on default scanline. Try to reset material slot and add only default gray on your model. If you have light on scene try to turn them off.
whell i get these kind of render times when i have materials and lighets in the scene .. for a simple clay render without lights it takes me like 10 min tops .... with amterials and without lights 1-2 hours ... and when i add lights ... well ... from the the fun starts ... i tryied all that you've said the first time i saw the problem