I don't consider this as a test to check if your anti-virus is really good
I consider it as just a test for the software to be eligible to become an anti-virus
The anti-virus will itself prove good to you if:
- you are infected by any virus and your anti-vrus detects and cleans/removes it
- your anti-virus prevents your machine to be attached by network attacks
- and many other important activities...
without consuming a big chunk of your ram
You may look into the below links for more info: