With the help and counsel of the poeple here in the Forum, I recently upgraded to a system with Athlon 2400+, 512 RAM and ATI Radeon vcard with 128 videoRAM. Works wonderfully. So, as TJohn said, I begun to make scenes more and more complex, and at the end my rendertimes are exactly like before :) Rendertimes are only affected by CPU. Also, RAM helps you handle big files and, if you have another job like me, allows you to work and render at the same time. S.