 |
 | Home | Contact Us | FAQ | Search & Site Map | Link to Us |
 | Sign In | Join | Other 45 Sites in Network |
.NET Forum / .NET Framework / New Users / July 2005Format of .NET assemblies
Hi, I have few questions about the format of .NET assemblies: Are all .NET assemblies created in Portable Executable (PE) format only or is there any other format supported? If so, which format gives better performance? Is Common Object File Format (COFF) related to .NET assemblies? Thanks in advance, Ravi. >Are all .NET assemblies created in Portable Executable (PE) format only or >is there any other format supported? If you target 64-bit platforms they can also be in PE+/PE64, if you count that as a separate format. >Is Common Object File Format (COFF) related to .NET assemblies? Yes, since it's related to PE. Mattias  SignatureMattias Sjögren [MVP] mattias @ mvps.org http://www.msjogren.net/dotnet/ | http://www.dotnetinterop.com Please reply only to the newsgroup. Hi, Thanks for the reply. From my understanding, the code in PE format is the MSIL. During execution, the JIT compiler converts MSIL to native code and executes it. Is there a way to pre-convert MSIL into native code to avoid runtime overhead? What is the format in which the native code is stored? (is it COFF even for managed code also?) Thanks, Ravi. > >Are all .NET assemblies created in Portable Executable (PE) format only or > >is there any other format supported? [quoted text clipped - 7 lines] > > Mattias Well you can run NGEN.EXE on the assembly on the deployment machine - this will cache a native image ono the disk. Is this an overhead you are theoretically worried about or do you have evidence that JIT compilation is cauing you problems in your environment? NGEN doesn't come for free, there are also downsides to using it in 1.x (although some of these have been resolved with NGEN v2.0) Regards Richard Blewett - DevelopMentor http://www.dotnetconsult.co.uk/weblog http://www.dotnetconsult.co.uk Hi, Thanks for the reply. From my understanding, the code in PE format is the MSIL. During execution, the JIT compiler converts MSIL to native code and executes it. Is there a way to pre-convert MSIL into native code to avoid runtime overhead? What is the format in which the native code is stored? (is it COFF even for managed code also?) Hi, There is no evidence that JIT causes problems, but it is a theoretical assumption that if we run a native executable, it would run faster. Are there any problems with using NGEN.exe? Thanks, Ravi. Are there any > Well you can run NGEN.EXE on the assembly on the deployment machine - this will cache a native image ono the disk. > [quoted text clipped - 15 lines] > What is the format in which the native code is stored? (is it COFF even for > managed code also?) An NGEN'd assembly will not run faster except at start up (code is only JIT'd once per program executing). However, in 1.1 NGEN code *may* run slower as the runtime has to load both the native version and the IL version as the IL version contains the metadata the runtime needs to provide alot of the services it does. Because of the impact on working set, the program may, therefore have more paging taking place and so run slower. In addition, NGEN'd assemblies are "fragile" in that if any dependency changes the runtime must assume that any inlined methods may now be invalid and so reverts back to JITing. However, Windows likes to share code images across processes which it cannot do with JIT'd code so NGEN can give an advantage there - but this depends on you NGENing an image that is used by alot of processes. Version 2.0 puts the metadata in the native image to resolve the double load issue and has a background process that re-NGENs native assemblies that have been "broken" by dependency changes. So under version 2.0 NGEN is much morfe compelling. However, as with all performance optimizations make sure you test that it has helped before you go into production with it. NGEN can help speed up start up time but won't necessarily. Regards Richard Blewett - DevelopMentor http://www.dotnetconsult.co.uk/weblog http://www.dotnetconsult.co.uk Hi, There is no evidence that JIT causes problems, but it is a theoretical assumption that if we run a native executable, it would run faster. Are there any problems with using NGEN.exe? Thanks, Ravi. Are there any "Richard Blewett [DevelopMentor]" wrote: > Well you can run NGEN.EXE on the assembly on the deployment machine - this will cache a native image ono the disk. > > Is this an overhead you are theoretically worried about or do you have evidence that JIT compilation is cauing you problems in your environment? NGEN doesn't come for free, there are also downsides to using it in 1.x (although some of these have been resolved with NGEN v2.0) You could use the "ngen" to compile your MSIL code. It could perhaps save a bit especially at startup... Other than that it's likely that the algoirhtms used will likely influence much more the performance than the file format.... Patrice > Hi, > [quoted text clipped - 8 lines] > Thanks in advance, > Ravi. Well, I don't think that at runtime you'll see any difference. I remember reading some white paper from nasa (or some org like that) showing with a math benchmark that the managed code is as fast as the native one, and sometime maybe is faster! > You could use the "ngen" to compile your MSIL code. It could perhaps save a > bit especially at startup... [quoted text clipped - 16 lines] > > Thanks in advance, > > Ravi. You can start from here http://msdn.microsoft.com/msdnmag/issues/02/02/PE/default.aspx HTH Alex > Well, I don't think that at runtime you'll see any difference. I remember > reading some white paper from nasa (or some org like that) showing with a [quoted text clipped - 21 lines] > > > Thanks in advance, > > > Ravi. Free MagazinesGet these publications absolutely FREE for up to 12 months. There are no hidden fees and no obligation. Simply choose a title, complete the application form and submit it. Read more ...
|
Reply to this Message
|
 Sign In
 Join
 My Latest Posts My Monitored Threads My Blog My Photo Gallery My Profile My Homepage Start New Thread Enable EMail Alerts Rate this Thread
|
©2008 Advenet LLC Privacy Policy - Terms of Use
This website includes both content owned or controlled by Advenet as well as content owned or controlled by third parties.