hey why go for mc afee, I am not against it, but I feel you canuse the AVG anti virus, it is far better than mc afee, and it's scanning and virus identifying rate of virus es in copressed as well as uncompressed files is greater than norton too.
also, it consumes least ram around 2MB.
I am a very happy customer of AVG, I use free ediion and it is fine because it is free and we can get regular updates so our database will be always updated.
you can check this
even it donot slow down your inernet speed.
any connection will not give high transfer rates at peak times.
so check avg which you may find better