We do our best in terms of ReSharper performance, however there are some known and unknown cases where ReSharper can slow down Visual Studio.
Here are some key points to troubleshoot and fix the performance issues with ReSharper.
Hardware. Though the recommended hardware is Dual-Core CPU and 4 Gb RAM, this configuration can be a bottleneck when working with ReSharper on a big-sized solutions. Adding more RAM and using a Solid State Drive (SSD) instead of HDD can help a lot.
OS. ReSharper is operating with memory a lot, so we recommend to use modern x64 OS, like Windows 7 x64 and Windows 8 x64. Old operation systems, like Windows XP, are known to be a cause of the poor performance.
Visual Studio configuration. ReSharper may conflict with the other Visual Studio addins and extensions - in case of slowdowns, please try to disable the other addins one-by-one and check if it helps to speed up VS with ReSharper. Here are some examples of known compatibility issues with other addins:
Productivity Power Tools
Also, you may try turning off the following options under "Tools | Options | Environment | General":
Automatically adjust visual experience based on client performance
Use hardware graphics acceleration if available
ReSharper configuration. Though ReSharper provides quite a few powerful and useful features, some of them can be tweaked or turned off in terms of improving the speed. Here are some examples:
Turn off Solution Wide Analysis (SWA) in "ReSharper | Options | Code Inspection | Settings", 'Analyze errors in whole solution' checkbox
Switch back to Visual Studio IntelliSense in "ReSharper | Options | Environment | IntelliSense | General" dialog
Clearing caches for current solution in "ReSharper | Options | Environment | General" dialog
Verifying that slowdown is caused by ReSharper. To do that, simply suspend ReSharper as described here and check if performance issues are still present.
Using built-in dotTrace Performance Profiler core. If performance issues are crucial, you may capture a performance snapshot and upload it to JetBrains Team, so we can investigate the performance issue you encounter and give some specific recommendations for you.
In the ReSharper 7.x and 8.x you may do with 'ReSharper | Help | Profile Visual Studio'.
In ReSharper 9.x and above, please go to 'ReSharper | Help | Report a Bug or Submit Feedback...', select "Performance Problem" issue category and use "Attachments | Performance Snapshot". Note: on a 1st run self-profiling tool will be downloaded from JetBrains server, so please be patient.
This action will start the profiling of the VS immediately - after you finish doing the repro actions (basically, reproduce the slowdown), please press the 'Get Snapshot' button in the dialog. After profiling is complete, you 'll be able to upload the snapshot to our FTP server, so we could investigate it to provide a solution and/or bugfix for the performance issues.