Since the S.M.A.R.T. data on the drive doesn't indicate any problem, you're likely dealing with either an application that's using the drive excessively, or an I/O subsystem bottleneck.
Narrow it down to any offending process(es)
- Open Windows Task Manager
- Select the Processes tab
- Select View->Select Columns
- Enable the I/O Read Bytes and I/O Write Bytes columns and press OK
- Press the 'Show processes from all users' button
- Click on the Image Name column header so processes are sorted by name (minimizes them bouncing around)
- Monitor the previously enabled columns and terminate any non-critical processes (sql server, firefox, etc.) one-by-one, checking system performance after terminating each one to see if it was the offender
If you find a process that's causing the problem, you'll have to deal with that as a separate issue (maybe it will just need to be updated for a bugfix).
Check I/O subsystem performance
If you didn't find an offending process, you should find a benchmarking tool (since you've already used CrystalDiskInfo, I recommend CrystalDiskMark). Run a benchmark on the drive and search the web for other peoples' results using the same benchmark program on the same or similar type of drive, and see if your drive's performance is reasonably close. Post your benchmark results here too so we can see them.
Update drivers
If neither of the above shed light on the issue, try installing updated drivers from the system manufacturer's website.
2Have you used the Resource Monitor to figure out exactly what's using the disk yet? If not, do that first. – Ƭᴇcʜιᴇ007 – 2015-08-11T15:31:49.500
1Rather than look at the
Performance
tab of WindowsTask Manager
look at theProcess
tab. Then click theDisk
Column heading until is shows the "sort descending" icon (a down arrow head) and see what program/process is taking up room. Also how much free disk space do you have remaining? – albal – 2015-08-11T15:33:57.007The programs and processes change on a regular basis, at the moment its sql server, firefox, mcafee, tortoisesvn – Ben Whyall – 2015-08-11T15:51:56.323
Check for a failing disk (SMART test). See Util to check external USB Drive health? for some possibilities.
– DavidPostill – 2015-08-11T17:09:25.810Might also be possible under extreme circumstances where the disk is severely fragmented (run the fragmentation), multiple anti-virus softwares deadlocking themselves, or a virus/zombie/bitcoin-generator being hosted on the machine (are you running micro-torrent?). – rlb.usa – 2015-08-11T18:34:45.063