I forgot to post this for reading.
Virus detection is a computationally intensive mathematical problem
requiring structural analysis, checksum calculation and mathematical data
conversions. Processor time is therefore the main resource consumed by the
Anti-Virus, and each new virus added to the anti-virus database increases
the overall scanning time.
Other anti-virus products speed up scanning by excluding from their
databases both viruses which are less easily detectable or less frequent in
the geographic location of the anti-virus vendor, and file formats that
require complicated analysis (e.g., PDF).
Kaspersky Lab believes that the purpose of anti-virus protection is to
establish real and complete anti-virus security for its users.
Experienced users can, of course, accelerate anti-virus scanning by
disabling scanning of various file types. However, please keep in mind that
it will decrease the overall security level.
Kaspersky Anti-Virus recognizes more than 700 formats of archived and packed
files. This is essential for anti-virus security because harmful executable
code may be hidden inside files of any recognized format. However, despite
the daily growth in the number of viruses detected by Kaspersky Anti-Virus
(approximately 30 new viruses appear daily) as well as the ever increasing
number of recognized file formats, this new version of our product functions
faster than previous ones. That is achieved through the use of new unique
technologies, such as iChecker™ and iStreams™, developed at Kaspersky Lab.