Microsoft today released the fifth preview build of Visual Studio '15', keeping to what seems to be an every month-and-a-half schedule. The last was offered in mid-August, with Preview 3 in early July.
The company has been promising all along that this version of its IDE would be lighter-weight, and it's promising even more performance improvements in Preview 5. You can check out a side-by-side video here.
Here's what Microsoft is listing as "key performance gains" in this build:
Shorter solution load time with lightweight project load: Working on solutions that contain upwards of 100 projects doesn’t mean you need to work with all the files or projects at a given time. VS “15” provides editing and debugging functionality without waiting for Visual Studio to load every project. You can try out this capability with managed projects in Preview 5 by turning on “Lightweight Solution Load” from Tools -> Options -> Projects and Solutions.
Faster startup with on-demand loading of extensions: The idea is simple: load extensions when they’re needed, rather than when VS starts. In Preview 5 we started this effort by moving our Python and Xamarin extensions to load on demand and are working on moving all extensions we ship with Visual Studio and extensions shipped by third party extension vendors to this model. Curious about which extensions impact startup, solution load, and typing performance? You can see this information in Help -> Manage Visual Studio Performance. Do you develop an extension? We will be publishing guidance to help extension developers move to on-demand loading.
Faster project load, coding, and debugging for C++: We have made loading C++ projects faster. Check out this video showing the improvement. You can enable this by setting “Enable Faster Project Load” to True from Tools -> Options -> Text Editor -> C/C++ -> Experimental. We have also made improvements to our linker and PDB loading libraries to make incremental builds and launching the debugger much faster while significantly reducing memory consumption while debugging.
Improved speed of Git source control operations by using git.exe: We have improved debugging performance by optimizing initialization and other costs related to IntelliTrace and the Diagnostic Tools window, and removed several delays that occur when editing and switching between XAML files.
There are quite a few other improvements as well. Microsoft says that these features are aimed at keeping productivity high, and you can read more about them here. You can also find the release notes here, which include known issues.
As always, the company warns that this is an unsupported preview build, so you shouldn't install it on machines that you rely on for "critical work". You should, however, be able to run it side-by-side with Visual Studio 2015.