Overall McAfee Internet Security 2011 had the least impact on system performance, with faster-than-average scores in all 13 tests, and very good scan speeds. On the opposite end, PCTools added the most latency in nearly all the tests despite having the fastest on-access scanning speeds. While top-ranking Norton Internet Security wasn't as light in impact on system performance as McAfee, it had better than average scores overall, though performance dragged a little more than average in a couple of tests. For on-demand scanning speed, Eset had the fastest score.

The overall score for each suite takes into account various aspects of malware detection, blocking, and cleanup; the feature set; and ease of use. However, malware detection, blocking, and cleanup account for the lion's share of the scoring.

For more on our testing, see "."

Here's a summary of our findings on each suite, with links to the full reviews.

Symantec Norton Internet Security 2011