VS2008 SP1 and .NET FX Beta Performance Improvements
You probably already saw Soma’s Blog on the Beta for Visual Studio 2008 and .NET FX 3.5 SP1. If you can, please download and install the Beta quickly (be sure to read the readme for Visual Studio Professional and for Visual Studio Team System first). The sooner we get your feedback, the sooner we can act on it.
Visual Studio 2008 SP1 is packed with new features, major updates to frameworks, and fixes. So much so that with everything installed (including x64 and ia86 support) you would need to download and install about 1GB of updates. Which brings us to the first and most important performance improvement – you only download what you need!
VS2008 SP1 includes a new installation / update engine. You just download the installer, which then analyzes your system installation, and only downloads the components you need. Thus a default installation of VS2008 Team System will only download about 600mb (and less still if you don’t have all the default components installed). Download performance will vary substantially based on your internet connection and network contention; however, it generally outperforms an IE file download, and will automatically restart in the middle if your network connection drops out and comes back. (However, if you cancel the install, it will restart at the beginning.)
The new installation engine is also much faster than VS2005 SP1, installing twice as much updates in less than half the time (typical install time is about an hour, if you’re running Vista RTM, you’ll want to upgrade to Vista SP1 before installing VS 2008 SP1, it’s much faster).
(The Express versions of VS SP1 are re-releases, not patches; however, they still use the intelligent patching/download logic for .NET FX and other components).
Here are some of the other performance improvements in Visual Studio 2008 SP1 and .NET FX 3.5 SP1 (includes .NET FX 2.0 SP2 and .NET FX 3.0 SP2):
· Improvements in the WPF designer including a (10-20%) improvement in startup time.
· Improvements working with ASPX forms, Java Script, and web site building. Some parts previously released as KB946581.
· Improve Visual Basic build performance for projects that contain a large number of XML comments in a single file (such as a designer-generated dataset or web reference). Previously released as KB946344.
· Improved working set and startup times for NGEN’d images (varies substantially by app).
· Support for Address Space Layout Randomization (ASLR) on Vista and WS 2008. Uses fast kernel mode virtual base address relocation to improve memory layout and security.
· Improvements in symbol and source downloading and the ability to cancel symbol download from slow symbol servers.
· Fix to a performance problem in the debugger when you are stepping through source code that is downloaded from Microsoft Reference Source Server that was caused by downloading the source files again for each breakpoint. Previously released as KB944899. (Note this fix is included in SP1. To improve the SP1 install experience, please uninstall this KB before installing the SP.)
Team Foundation Server (TFS):
Brian Harry has already blogged about some of the great things in this release. Here’s what he said about performance and scalability improvements:
· # of projects per server - Constraints on the number of projects per server have been written about quite a bit. In TFS 2008 SP1, we have made some important improvements. To refresh your memory, the primary issue is that the size of the cache that the TFS client downloads is proportional to the number of projects on the server. This cache can get very large (10s of MBs) and slow things down to the point that usability is affected. The changes we have made for SP1 include:
o Only download metadata for projects a user has access to. By only granting access to the projects a user needs, it will dramatically reduce the size of the metadata they download.
o Implemented cache compaction to remove some stale data from the cache that is no longer used. We have seen 30% or better improvements from this in some circumstances.
o Improved the speed of the Connect To TFS experience when there are a large number of projects in the list. We saw about an 80X improvement on one of our internal servers.
· Improved syncing identities from Active Directory - Our tests show syncing a group with 200,000 users dropped from 69 minutes to about 10 minutes. This can significantly reduce background overhead on a system with lots of users.
· Improved checkin concurrency - Checkins are globally serialized - meaning 2 checkins (overlapping or not) must be processed in order and the second must wait on the first to complete. In SP1, we were able to both improve the overall speed of checkin and reduce the blocking. The blocking period is now only about 1/3rd of the checkin time.
· tf branch /checkin - Creating new branches when they are large (ours are about 1,000,000 files) can be very time consuming. We have created an option for creating a branch that is much faster. tf branch /checkin creates the branch without first pending the changes and requiring a subsequent checkin operation. The result is about a 10X improvement in branch creation speed.
· Online index rebuilding - If you use SQL Enterprise with TFS, TFS will now rebuild indexes online allowing for less "downtime" for maintenance. If you use SQL Standard (which comes with TFS), then you will still get offline index rebuilding and your TFS server will not be responsive during weekly maintenance jobs. If your TFS database is small, it doesn't really matter but as it gets into the terra-bytes, online index rebuilds become a must.
· Team build support for very large checkins - In TFS 2008 and previous versions, a very large checkin (hundreds of thousands of files) would trigger an out of memory error in TFS Build and prevent CI builds from triggering. The out of memory issue has been fixed in SP1 and all checkins should properly trigger builds.
· Faster security manager - We found an O(N^2) algorithm in the security manager for version control and have replaced it with an O(N) algorithm. It will help version control performance across the board. We found it on large Get operations (getting hundreds of thousands of files). The change reduced the security manager time from 5-6 minutes to a few seconds. The end result is that those gets were about twice as fast.
· tf get /remap - Kind of a complicated feature but dang handy if you need it. This is a new option on tf get that is intended to be used when you want to switch your workspace from one branch to another in the same code base. You first change the workspace mapping and then issue a tf get /remap. Because a large percentage of the files in two related branches are frequently identical, this command optimizes for that. Rather than downloading all the content, it will only download the things that are different between the two branches. I can reduce the get of a very large workspace from 10's of minutes to a few seconds.
· Much, much more... - This is just a taste of the performance improvements we've made. As always, each release includes a roll up of performance improvements we've made for our own internal dogfooding of TFS. This release is no different. There are dozens of additional fixes that we've made to improve performance. If your installation is very large, you should notice nice responsiveness improvements across the board.
Additionally, this release does include KB947551 that some of you asked about (Improved right click to context menu performance on a project or solution in "Solution Explorer" with a large number of projects in TFS).
We’ve made some substantial improvements in WPF performance. Some of these you get for free by just installing SP1, others require you to take advantage of new components or options. See the WPF Performance Blog for all the details.
· Up to an 80% improvement in server to client sync services in ADO.NET.
Visual Studio Data Professional:
· Up to 5x faster (re)loading database projects (than VS2008 RTM).
· Up to 2x faster importing an existing schema (than VS2008 RTM).
Known Performance Issues in Visual Studio 2008 SP1 that are still outstanding:
· We haven’t yet fully resolved some Web Editing issues where you may experience poor performance when typing in design view or during design/source view switch.
· In the new Data Entity support UndoDeleteProductEntity is slower than we’d like, we expect to fix it for RTM.
Of course, as mentioned before if you have any performance problems, we’d like to hear about them. For issues related to the Beta, please use the community forum: http://forums.microsoft.com/MSDN/ShowForum.aspx?ForumID=2136\&SiteID=1
For issues unrelated to the Beta, you have the usual choices:
1) You can log bugs on Connect. Bugs logged there go directly into our bug tracking system and Connect provides a mechanism for communication, tracking, status, and other customers to comment.
2) You can e-mail the Performance Team directly at DevPerf@Microsoft.com.
3) You can post comments on this blog (you may need to sign-in first).
Senior Program Manager
Developer Division Performance Engineering Team