McAfee can slow down your computer during full system scans. However, modern versions of McAfee are designed to have minimal impact on everyday use. If McAfee is causing noticeable slowdowns, the fixes are: schedule scans for when you’re not using your PC, reduce McAfee’s CPU priority, update McAfee, or check for conflicting software.
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Why Does McAfee Slow Down My Computer?
McAfee uses system resources (CPU, RAM, and disk access) to scan files in real time and run scheduled full scans. The most common causes of McAfee-related slowdowns are:
- Full system scan running in background — McAfee scans every file on your hard drive
- McAfee updating its virus database — database downloads can temporarily slow connections
- McAfee starting up with Windows — adds to boot time
- Outdated McAfee version — older versions are less efficient
- Low RAM on older PCs — McAfee requires at least 2GB RAM to run smoothly
6 Fixes to Stop McAfee Slowing Down Your Computer
Fix 1: Schedule Scans for Off-Hours
- Open McAfee and click PC Security
- Select Scheduled Scans
- Change the scan schedule to overnight or when you are not using your PC (e.g. 2:00 AM)
- Click Save
Fix 2: Run a Quick Scan Instead of a Full Scan
Full scans check every file on your hard drive and can take hours. Quick Scans only check areas most likely to be infected (startup files, running processes, system areas) and take 5–10 minutes. For most users, weekly Quick Scans are sufficient.
Fix 3: Update McAfee to the Latest Version
Older McAfee versions are less efficient. Open McAfee, click the gear icon, go to About, and check for updates. Installing the latest version often significantly improves performance.
Fix 4: Disable McAfee Performance Monitoring (if not needed)
- Open McAfee
- Go to PC Security > Real-Time Scanning
- Click Configure
- Under Files opened, change from ‘All files’ to ‘Default files and programs’
Fix 5: Exclude Non-Essential Folders from Scanning
Adding frequently-accessed folders (like your work documents or game folders) to McAfee’s exclusion list prevents constant re-scanning of trusted files:
- Open McAfee > PC Security > Real-Time Scanning
- Click Add file or Excluded files and folders
- Add folders you trust (e.g. C:\Work\Documents)
- Save the exclusions
Fix 6: Upgrade Your Hardware
If your PC has less than 4GB RAM or is more than 8 years old, McAfee (and all modern software) will feel sluggish. Consider upgrading RAM or switching to a Solid State Drive (SSD) for a significant performance boost.
Does McAfee Use a Lot of RAM?
McAfee typically uses 150–300MB of RAM during normal operation (real-time scanning running). During a full system scan, RAM usage increases to 400–600MB. On a PC with 4GB or more RAM, this is not a problem. On older PCs with 2GB RAM, McAfee may cause noticeable slowdowns.
How Much Does McAfee Slow Down Windows 10/11?
In AV-TEST performance benchmarks, McAfee scores 15–17/18 on performance impact — meaning it has a measurable but generally acceptable impact. The test simulates everyday PC use including web browsing, document editing, file copying, and software installation. For most modern PCs, McAfee’s performance impact is minimal.
