AV-TEST　7月 8月
https://www.av-test.org/en/antivirus/home-windows/windows-10/august-2018/

Slowing-down when launching popular websites

Standard PC (Intel i3-6100, 256 SSD, 8GB RAM)
*5% PCMatic, WindowsDefender
*6% Avira, K7, McAfee
11% BullGuard
12% F-Secure, Norton
13% Vipre
15% Comodo
18% AhnLab, eScan
19% TrendMicro
22% Kaspersky
23% AVG
25% Bitdefender
29% Avast, GData

High end PC (Intel i7-7700, 256 SSD, 16GB RAM)
*6% McAfee, PCMatic
*7% Vipre
*8% AhnLab, Norton
*9% K7
10% WindowsDefender
11% Avira
12% F-Secure
14% BullGuard, GData
17% Avast, Kaspersky, eScan
18% Comodo
22% AVG, Bitdefender
29% TrendMicro