Hello all,
I've just upgraded to a new PC and am now experiencing slow XNA project builds. The culprit seems to be content pipeline texture importing, which is taking approx. 4 seconds per imported texture.
This ran blindingly fast on my old PC, which was a 32 bit XP install on an Intel P4 2.4GHz hyperthreaded CPU with a GeForce 6800 graphics card. The new PC is a 64 bit Vista install on an Intel Core 2 Duo 3.0 GHz CPU with a GeForce 8800 GT graphics card. Both machines are fully patched with Windows Update and running the latest NVidia ForceWare drivers. Both are running DirectX retail, both report no issues in dxdiag, and the CPU and hard drive are essentially idle other than performing the build (verified with Task Manager and SysInternals' Process Monitor.) Nor are there any unusual processes running, or processes which also make use of Direct3D.
I managed to reproduce this in a very simple case. I put a test.png file (48 x 48 pixels, 557 bytes) into a new folder, and added the following msbuild script as test.xml:
<Project DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
<PropertyGroup>
<XnaPlatform>Windows</XnaPlatform>
<XnaFrameworkVersion>v2.0</XnaFrameworkVersion>
</PropertyGroup>
<ItemGroup>
<Reference Include="Microsoft.Xna.Framework.Content.Pipeline.TextureImporter, Version=2.0.0.0, Culture=neutral, PublicKeyToken=6d5c3888ef60e27d, processorArchitecture=MSIL">
<Private>False</Private>
</Reference>
</ItemGroup>
<ItemGroup>
<Compile Include="Test.png">
<Name>Test</Name>
<Importer>TextureImporter</Importer>
<Processor>TextureProcessor</Processor>
</Compile>
</ItemGroup>
<Import Project="$(MSBuildExtensionsPath)\Microsoft\XNA Game Studio\v2.0\Microsoft.Xna.GameStudio.ContentPipeline.targets" />
</Project>
I invoke msbuild and get the following output:
> msbuild /target:Clean,Build test.xml
Microsoft (R) Build Engine Version 2.0.50727.1434
[Microsoft .NET Framework, Version 2.0.50727.1434]
Copyright (C) Microsoft Corporation 2005. All rights reserved.
Build started 27/04/2008 15:29:20.
__________________________________________________
Project "[...]\test.xml" (Clean;Build target(s)):
Target XNAContentClean:
Deleting content pipeline output files
Target CoreClean:
Deleting file "[...]\obj\Debug\ResolveAssemblyReference.cache".
Target CoreCompile:
Building Test.png -> bin\Debug\Content\Test.xnb
Rebuilding because asset is new
Importing Test.png with Microsoft.Xna.Framework.Content.Pipeline.TextureImporter
Processing Test.png with Microsoft.Xna.Framework.Content.Pipeline.Processors.TextureProcessor
Compiling bin\Debug\Content\Test.xnb
Build succeeded.
0 Warning(s)
0 Error(s)
Time Elapsed 00:00:11.51
Which as you can see is quite a pitiful build time for a single texture. But even allowing that the MSBuild setup/teardown may account for a lot of this time, I've noticed that 4 seconds of that is taken up by the stage "Import Test.png with ...TextureImporter", and this is the bit which concerns me most.
I ran a CLR profiler against msbuild, and tracked the main slowdown to inside TextureImporter itself. The biggest overhead is
TextureImporter.Import which calls TextureImporter.InitD3D, which calls CommonHelperFunctions.InitD3D(), which takes 3.44 seconds to execute.
Inside CommonHelperFunctions.InitD3D(), there are 3 function calls. CommonHelperFunctions.CreateDummyWindow() takes 0.93 seconds. <Module>.Direct3DCreate() takes 0.67 seconds. Direct3DBundle..ctor() takes 0.00 seconds. The rest of the method body takes up 1.84 seconds.
My profiler couldn't pick it up, but running Reflector on CommonHelperFunctions.InitD3D() I can see there's a somewhat indirected function call to IDirect3D::CreateDevice() in there. Since the rest of the method, other than the aforementioned calls, is just doing some memory clearing and copying, I assume this call takes about 1.84 seconds.
I think I've gone about as far as I can in investigating it. So my question is, does anyone have any ideas as to why this is so slow? For projects with lots of textures, my clean build times are getting a little crazy.
