How much does anti-virus software affect computer speed?

I have Norton Internet Security.

How much does anti-virus software affect computer speed?antivirus

I had Norton, but got rid of it.

Too many conflicts with other programs.

Let me give you an example.

To download Adobe would take 17 hours.

With anti-virus, etc., software turned off: less than 1 hour.

Go figure.

How much does anti-virus software affect computer speed?computer

It wil take a good chun out of your performance.

its best to run it at its lowest priority or when the machine is not in heavy use.
With NIS, I think its around 20-40%, if you have dualcore CPU, then that will make it much faster.
Norton from what I hear is a resource hog. I use CA and I don't even know it's there.
allot dude allot maybe 1 8th thats what i'm thinkin