How we test: Antivirus software
Antivirus programs are designed to detect and intercept harmful files downloaded to your computer. In order to monitor incoming files, though, antivirus programs--like all applications--need to use system resources. The degree to which an antivirus program detrimentally affects a system's performance varies from one application to another. CNET Labs tests three areas of antivirus application performance: how deep-file virus scanning impacts overall system performance, how quickly files can be scanned for viruses, and how system boot time is affected by the antivirus program.Test environment
Antivirus software is tested on a Dell Inspiron 530 desktop system with a Core 2 Duo E4500 processor running at 2.20Ghz, 4GB of DDR2 SDRAM running at 677MHz, an Nvidia GeForce 8300 GS PCI-Express graphics card with 256MB of memory, a 320GB Western Digital hard drive, and Windows 7 Ultimate 64-bit with the latest security updates installed. Once the antivirus software being tested is installed, we make sure the most recently available updates are installed, including the latest virus definitions. We test using the antivirus program's default settings.System-performance impact test
Actively scanning a system for viruses can have an adverse affect on overall system performance, as the antivirus engine competes with other applications for system resources. When performing regular real-time scans, most of today's antivirus scan engines are sophisticated enough to relegate the additional overhead they introduce to the background and don't significantly affect the performance of other applications. Performing deep scans, on the other hand, often requires enough of the available system resources for the antivirus engine to have a noticeable effect on the performance of other applications. Deep scanning is when the antivirus application scans every file located on all partitions found on each drive. This set of tests is designed to measure how much performance degradation selected applications suffer when a deep scan is taking place. We first run the three tests listed below, before an antivirus application is installed. We then install the antivirus app and run the same tests again--this time while the antivirus program is performing a deep scan of the system.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, 302MB MOV file. While the video conversion takes place in the foreground, iTunes converts a group of 128Kbps MP3 files into 128Kbps AAC files.
This test's score is based on how long it takes a system to perform only the QuickTime conversion. The iTunes conversion taking place in the background is designed to significantly increase the overall CPU workload and to create a true multitasking environment. This test exercises nearly every major subsystem, including the CPU, the memory, and the hard drive. Desktops with multicore CPUs are likely to perform better than comparable systems that use CPUs with fewer cores or single-core CPUs.
This test utilizes Microsoft's Word 2003, Excel 2003, and PowerPoint 2003 from Microsoft Office 2003.
The test starts with Word running a macro, which performs a number of functions on a document, such as searching and replacing, changing font sizes, and creating columns. Once the Word macro completes, Excel launches and runs a macro, which performs functions on a spreadsheet, such as editing formulas and creating charts. Next, PowerPoint runs a macro, which adds graphics and text and moves images around on three different presentations.
As soon as the test starts, a file copy also starts in the background, copying from one set of folders on the system's hard drive to another set of folders on the same drive. The resulting folders total 2.57GB in size. Once the copy completes, the 2.57GB folder is then compressed into a single 2.04GB ZIP file, also in the background.
This test's score is based on how long it takes a system to perform all of these tasks. Time is kept until the last task running completes.
This test exercises nearly every major subsystem, including CPU, memory, and hard drive. Desktops that have multicore CPUs are likely to perform better than comparable systems that use CPUs with fewer cores or single-core CPUs.
Cinebench is a 3D rendering test based on Maxon's 3D animation application, Cinema 4D. This test almost exclusively exercises a system's CPU capabilities. Cinebench supports multithreading up to 16 CPU cores, so desktops with multicore CPUs are likely to perform better than comparable systems that use CPUs with fewer cores or single-core CPUs.
