Antivirus scanning is an odd beast. Everybody wants to know the numbers, but the means with which the results are generated can be so various as to be meaningless. Moreover, we come back to real-world applicability. If you’re running a deep scan in the middle of the night, do you care if it takes 10 minutes or two hours? If, for some strange reason, you run a scan while working on other tasks, do you care so long as there’s no noticeable impact on system resources? Honestly, we don’t. But for those who like numbers as a way to grade product options, here goes.

The first full system scan will almost always be the slowest. This is because most AV products perform some caching. The rationale is that, provided no malware is detected in the system, why reinvent the wheel? Why burn a lot of time and cycles performing deep inspection on files that are already known to be safe? This is akin to doing a differential backup rather than a full system backup.
AVG and McAfee are the big surprises here. In fact, there almost seem to be two approaches to deep scanning. Is it a coincidence that AVG and Kaspersky are in the back half of AV-C’s missed samples results? Maybe, but so is Microsoft, which is our second-slowest scanner behind GFI.

Subsequent deep scans seem generally to accrue cached data until a steady performance level is reached. For example, our three subsequent scan times for Symantec were 29:50, 6:01, and 6:15. Microsoft progressed from 1790 seconds to 361 and 375, or just over six minutes. So, our mean times reported here are actually skewed to the high side in cases where caching progresses to an eventual baseline. The notable exception is GFI, which clearly does not cache and exhibited no drop-off from the first scan to subsequent scans.
- Antivirus Need...and Greed
- Contenders: AVG And GFI
- Contenders: Kaspersky And McAfee
- Contenders: Microsoft And Symantec
- How We Tested: Configuration
- How We Tested: Benchmarking
- Application Installation
- Boot Time
- Standby Time
- PCMark 7 Results
- PCMark 7 Results, Continued
- Web Page Load Time
- Scanning Time
- Do Antivirus Suites Have A Big Impact On Performance?
i think something is wrong with your numbers.
Also, the timing of this article was excellent. I had just been doing some research about what anti-virus software I should switch to, mainly based on performance, but I guess I just got all the information I needed.
I stopped using AV products on my personal systems back in 2003. Norton back then was god-awful on a Pentium 4 systems, seemingly crushing the life out of a system. Even with a first generation WD Raptor 36GB my P4 2.6 would choke not only with Norton, but also McAfee. I might not use AV software, but I do put it on my family members' systems when it doesn't kill performance. In that respect these modern solutions seem much better.
>>Apparently, this is somewhat like saying you can boil water at 230 degrees Fahrenheit instead of 260 degrees. As long as the water is at 212 degrees or higher, no one really cares.
i think something is wrong with your numbers.
I had kaspersky on my intel i7-920 system with a SSD app/boot drive, and kaspersky brought my system to it's knees compared to a clean system without any antivirus. It was like a computer from 7 years ago in it's response time. Try to install something? Took 10 seconds to start the pre-scan, then it would pre-scan and then install was slower. Run firefox from a fresh boot? Wait 3 seconds. 3 seconds? With a SSD?
I removed it and tried out norton internet security and everything is instant like my clean system. I don't even notice that I have it most of the time. I attribute that partially to my good system, but I attribute the other part to it not just adding arbitrary wait times onto everything I try to do. Use that processor! I have multiple more to spare!
I know people think dirty of Norton, but as long as it protects me while pretty much being invisible to my performance to the naked eye, I'll give the once slow kid in the class if he's a genius now. I don't know why, but it works.
Tom's something is wrong with your test bench.
If anyone is interested, I did ran my own tests for most of the latest security suites and have reached to the conclusion that Avast 6 is the fastest around. A scan on 10 GB of data on an SSD took ~2 minutes , compared to 8 minutes it that took Kaspersky to finish the same job.
I agree that Avira free should have also been included to balance the field a little bit.