The slower update/download times of the definition file is due to the fact it has grown in size.
We have been increasing the rate of adding threats to detection this last year and this has of course increased the size of the file.
Implication: longer download/update times.
Customers of Ad-Aware Plus and Pro will also download virus definitions and the first update after activation will include the antivirus software modules.
This adds time to the download, of course. (Note: Anti-virus updates are never downloaded if you are using Ad-Aware Free).
Regarding slower scanning times:
After updating your software from Ad-Aware 2007 to 2008 the program will take longer time for the first scan you run. This relates to both Smart and Full scan.
After the initial scan, scanning times should decrease.
The scanning times may of course also relate to the number of threats in detection. The more stuff in detection that needs to be checked against, the longer time it takes. However, this is normally not noticeable with modern CPU's. The bottleneck of the scanning is the comparatively slow process of accessing the harddrive and scanning files.
Another factor to consider is if you are using the Plus and Pro versions and have enabled the 'Extended Anti-Virus engine' (turned on by default) the scanning times will also increase.
Besides large definition files and somewhat longer scanning times there should be no increase in the use of system resources. Of course, your system will be slower during a scan since it is accessing your drives.
If you have more than one logical harddisk drive (partition or secondary drive), try to move a really big file from one drive to the other and then see how much CPU resources it takes and how unresponsive your system gets.
Scanning a drive takes time and resources. The same for any scanning software. Simple as that.
If this is still a problem try this:
Open Settings->Scanning and enable "Run scan as background process" in the "Performance Tuning" section.
This will lower the priority of the process resulting in low use of resources but increased scanning times.
Edited by SpySentinel, 19 July 2008 - 10:16 PM.