I use two computers for three screens even though the option for three or more monitors from the one mchine was there (I can run three from my Dell - not sure what the vid card is.) In the end I liked the security of being able to not just back up my charting data but have it immediately available on a second machine in event of problems, corruption etc.
Problem of course was that my trading platform providor wont allow for multiple logins anyway so the second machine runs charts during the day and the other screens carry live data.
