Recently I noticed some of our machines are getting sluggish, mainly after boot-up. Using the Resource Monitor I detected excessive disk access from the system process with PID 4. Following some tips, I disabled the anti-virus on the System Volume Information folder, hoping it will help (I don't want to disable system restore).
However, it seems like PID 4 is accessing everything. When running a simple extraction of a ZIP file, I can see the WinRAR reading a few hundreds KBs per second from the file, but PID 4 reads dozens of MBs per second from the same file. After cancelling the operation, PID 4 keeps accessing the file for around 30 seconds, reading many MBs per second. This is not a Resource Monitor bug, as the disk is clearly active, and stops once resource monitors says PID 4 is finally resting.
Why is this miraculous process accessing everything every other process accesses?
I'm using the AVG antivirus. Disabling it did not change this behavior/
What is going on here?
Best Answer
This is an older question, but I had this issue, and for me it was SuperFetch. I tried everything I could find on PID 4 excessive hard drive usage, and some of it helped. A RAM upgrade from 4GB to 8GB only made the issue more obvious - RAM usage was low, no paging, but yet the hard drive was lit up for ~10 minutes after my laptop booted.
Long story short, there's a registry setting that controls what level of SuperFetch is appropriate. You can see below the EnableSuperfetch value is now set to 1, which seems to be "prefetch all executables and libraries". The default is a 3, which seems to mean "prefetch all executables, libraries, and documents". I have many documents, so I think this was taking way too long. Every document opened is another one that SuperFetch has to "analyze" to see how you're using it.
The registry key/value in question is:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management\PrefetchParameters\EnableSuperfetchSo far the only downside is that my outlook folders take a few extra seconds to open, and some commonly used documents like MS Project files take longer. But those delays pale in comparison to the disk thrash I was getting before!