Tycoon24 wrote:
Does [ClamXav] slow down your Mac when running scans?
I'll offer my experience, although I'm probably a poor example as I'm still using a slow iMac G5 these days.
I have ClamXav, MacScan, Sophos and VirusBarrier X5 installed with background scanning turned off on all of them. I occasionally run manual scans with each of them, mostly just as tests. I've never measured the differences (probably should if I had time), but subjectively they all have about an equal impact on CPU use, so if I'm using any of them to scan lots of files, I leave it to an overnight session. None of them slow me down as much as either TimeMachine backups or MobileMe updates, but of course those go quicker.
Another resource question would be how much RAM do they use, which again I have never accurately measured. I do know that ClamXav Sentry (the real-time-scanner) uses a significant amount of RAM because the entire signature database is loaded. This allows it to rapidly scan files which means no slow down, as long as you aren't trying to watch the entire hard drive. The OS produces an amazing amount of temporary files, so if you are trying to scan each of them it will be noticeable and it will fill up the scan log.