title: Process Explorer & Process Monitor: discrepancy in report of written bytes
body: <p>Recently, I read some articles about Firefox writing huge amounts of data to disk during everyday use and people being concerned about the health of their SSDs, so I decided to test it myself.</p>
  
  <p>I left Process Explorer running all day as I was using Firefox, and sure enough, it reported about 50 GB of "I/O Write Bytes" after some eight hours of use. Then I discovered Process Monitor, which records all system activity, including writes to specific files, so I thought I'll track down the offending files to try and find out the reason all that data gets written.</p>
  
  <p>The next day, however, after a full day of use monitored by both programs, Process Explorer showed me basically the same result, but Process Monitor showed only a couple of gigabytes written in total when I inspected the "Tools" menu → "File Summary" → "Write Bytes" column. (I didn't use any filters other than the process name being "firefox.exe".)</p>
  
  <p>Am I looking at the wrong data or is something else going on?</p>