The best antivirus software available does more than just stop computer viruses, it also addresses the myriad and complex modern threats that you'll encounter. Indeed, from the merged antivirus and anti-malware detection engines to enhancing online privacy controls, security suites are an essential part of Windows and Mac desktop life. And just like driving a car without wearing a seatbelt, you shouldn't try to get by can get by without using antivirus software just because you can.

Because of their long history of deleterious consequences to system performance, security suites deserve closer scrutiny than any other category of software.

Of course, it's important to look at how effective security suites are at stopping the bad guys. Any security suite, that can't hold up its responsibility to ensure your computer's protection isn't worth your time. Yet, there's another factor to consider. No matter how effective a security suite is, if it slows down your system too much you're not going to want to use it.

Trend Micro Premium Security 2013, with an interface optimized for Windows 8. Trend Micro

iTunes MP3-encoding test Using iTunes, we time how long it takes to convert 19 320Kbps MP3 tracks to 128Kbps AAC files, totaling 169MB. This test almost exclusively exercises a system's CPU capabilities. Apple iTunes supports multithreading, so desktops with multicore CPUs are likely to perform better than comparable systems that use CPUs with fewer cores or single-core CPUs.

Multimedia multitasking test We use Apple's QuickTime to convert a high-definition source video using QuickTime's "Movie to iPod" selection. The source file is an H.264-encoded, 30fps, 1, 920x1, 072-pixel, 302MB MOV file. While the video conversion takes place in the foreground, iTunes converts a group of 128Kbps MP3 files into 128Kbps AAC files.

Source: www.cnet.com