Virtual Instruments (VIs) hold out the promise that a few windows on your computer screen can effectively replace a roomful of expensive hardware instruments. But gargantuan sound libraries, integrated convolution reverbs, and exacting re-creations of classic analog synths can tax the limits of your computer's CPU, hard disk, and memory. A few tips and techniques can help you handle the balancing act of resource management and get the most out of the VIs you need for your tracks.