Graphic design or financial modeling software requires much more from a PC than other programs, and your clients who use those types of software need to have computers that can support it.
Remember how much your clients make when suggesting hardware. If they're making $60,000 a year and could make $1,000 more per month with better hardware, then this higher rate of pay can make a big difference for them.
Basically, get to know your users and the types of software they use so that you can make the appropriate suggestions. Learn more in the complete article (link above).
Added by Computer Consulting 101