I have seen several Day-Trading Platforms with multiple Monitors. HIGH SPEED graphics cards with plenty of onboard RAM as well as LOTS of system RAM is important. You don't want to be doing SWAPS and screen refreshes while executing a trade with 25 windows open! LOL Been there Done that! Several people I know who day-trade also use dual computers that are networked ONE for trading with dual monitors, ONE for email, alerts, research, news, & everything else you use a computer for. PLUS, you need a TV close by for the financial networks. OH YEA, most important.... LOTS OF MONEY for those bad days! LOL

Chief complaints I have seen were concerning:
too little RAM
Graphics Cards too slow
Monitors too small for viewing multiple windows
CPU speed slow
CONNECTION SPEED slow and unreliable