Help Setting Up Lan

Ok i have read and read online guides. i have not come across one that can help me with my problem. i have a crossover cable linking both computer. while playing an rts game. the game play slows down. ive asked around and no one seem to answer or help me. now what is it that i need in order to keep the game running at normal speed? i have a dell 410 core 2 duo 2.1 2Gb Memory at 667mhz 256Mb DDR3 video card. the other computer has 2.8 P4 h/t 256Mb DDR3 3Gb Memory. plz help i dont know what the issue is.