The Inquirer discovered a major limitation of ATI's CrossFire dual graphics card concept. They unveiled the master card needs the Silicon Image SiI 1161 chip which runs at 165MHz. By doing some maths they found out this chip can only support a 1600 x 1200 pixel resolution at 60Hz.
We also learned that this chip will be able to do 1280x1024 at 85 Hz and you can play with this equation on this very helpful site. we discovered that for 1600x1200 at 75 Hz you need at least 202.5 MHz clocked chip while for 1600x1200 at 85 Hz you need the chip that works at 229.5 MHz.