Severe SSD 100% usage and extremely high disk latency caused by AVG on Windows 10
I’m reporting what appears to be a serious performance issue related to AVG Antivirus on Windows 10.
For quite some time, my PC had extremely slow startup and disk performance issues:
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Windows took around 10 minutes to boot.
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Reaching the login/password screen could take several minutes.
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After entering my password, it could take another 4–5 minutes to reach the desktop.
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The computer could remain extremely slow for 30 minutes or more after startup.
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My SSD would stay at 90–100% active time, even though it was transferring very little data.
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The process apparently responsible would constantly change: System, Microsoft Edge, Steam, Logitech G Hub, AVG, Riot Client, Discord, etc.
Hardware / system
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Windows 10 (10.0.19045.6466)
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16 GB DDR4 RAM
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WD Green 2.5" 1 TB SATA SSD (system drive)
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SSD interface running at SATA/600
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SSD SMART health: 98%
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Temperature: ~33–34 °C
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No reallocated blocks
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No uncorrectable errors
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No command timeouts
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No CRC errors
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TRIM enabled
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The C: volume is not marked as dirty
RAM and CPU usage were also normal during the issue.
Disk behavior
The most concerning part was the SSD behavior.
During the problem, Windows Resource Monitor showed:
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100% disk active time
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Only around 4–8 MB/s total disk I/O
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Many unrelated processes simultaneously experiencing disk response times of approximately 500–700 ms
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Some operations taking 2–5 seconds
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One operation reached approximately 11,031 ms
For example, during one occurrence Resource Monitor showed operations from System, Edge, svchost, AVG, Riot Client, Steam and other unrelated applications all experiencing extremely high disk latency at the same time.
This made it look like whichever application happened to access the SSD was responsible for the 100% usage, rather than one specific application generating a large amount of I/O.
AVG file-system filters
I checked the loaded file-system minifilters using fltmc.
AVG had the following filters loaded:
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avgSP— 5 instances — altitude 388431 -
avgMonFlt— 5 instances — altitude 320730 -
avgSnx— 5 instances — altitude 137630
AVG processes and AVG files also appeared repeatedly in Resource Monitor during the high-latency periods.
What happened after uninstalling AVG
I completely uninstalled AVG and restarted the computer.
The difference was immediate.
On the first reboot after removing AVG:
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Windows booted almost instantly compared with the previous ~10-minute startup.
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The login-to-desktop transition was almost instant.
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The desktop was immediately responsive.
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I was able to open Microsoft Edge almost immediately after reaching the desktop, and it opened normally.
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The SSD still reached 100% active time for approximately 2–3 minutes after startup, but the computer remained responsive, unlike before.
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The previous behavior where the computer remained nearly unusable for tens of minutes disappeared.
No other hardware or Windows configuration changes were made before this test. The significant change was uninstalling AVG and rebooting.
Because of this A/B comparison, I strongly suspect AVG, or possibly one of its file-system minifilter drivers, was causing or severely amplifying disk I/O latency on my system.
I cannot say conclusively which AVG component is responsible, but the performance difference after uninstalling AVG is very significant.
Has anyone experienced similar behavior with AVG, especially 100% SSD active time with very low throughput and extremely high response times?
If an AVG developer or support representative sees this, I’m happy to provide additional diagnostic information if needed.