A few days ago ReSharper 4.5 Beta was released by JetBrains. This new version promise better performance and less memory consumption. New features include VB9 support, native MSTest support, "Go to Implementation" and improved compatibility with F#, Compact Framework and Silverlight.
Developers have complained about how slow Visual Studio becomes when having ReSharper installed. In this new version JetBrains promise 30% increase in performance for Solution or Web Site opening, 45% increase in code editing and 60% increase in search and navigation.
On their web site they explain the performance improvements in more detail:
We have managed to make ReSharper load and work faster and more smoothly in general, particularly on big (and we mean BIG) solutions. Wall-time measurements of solution loading show 20 to 40 percent acceleration until the solution is ready for code editing. Web site loading time has also been reduced by a third. A certain mixed-language solution consisting of about 15 thousand classes now takes only 70 seconds to load, and this includes making every ReSharper feature available. The list of significantly accelerated operations includes: renaming symbols, finding commonly used symbols, creating symbols from usage, and analyzing large XAML files. We've also cut down the volume of memory resources required to analyze jumbo autogenerated code files, which should especially benefit those who work with ASP.NET and LINQ to SQL.
Overall, the range of solutions that ReSharper is able to handle without degrading responsiveness is now wider than ever.
In previous releases the major focus has been on adding new features, but this release performance has been the number one priority:
We have moved on from extending the pool of ReSharper features to really scrutinizing its performance and memory usage — our key areas of focus when developing ReSharper 4.5.
They have however added some new features:
…in addition to significant achievements in these areas [performance], ReSharper 4.5 also brings a set of other improvements, including solution-wide code inspections, support for VB9, extended naming style configuration scheme, new and updated refactorings, and more.