my team is beginning a brand new project on asp.internet mvc, and that we are pondering what technology for data use of use, how can you think which is the greatest, that has the very best performance ? which is simpler to make use of and also to maintain ?

If .Internet 4., choose from NHibernate or Entity Framework. NHibernate is much more extensible and usually more feature wealthy. Entity Framework works more effectively for businesses that prefer to have what Microsoft provides. Both are valid options with no you have yet released a goal significant blow by blow comparison. This is among the better non-objective evaluations:

http://ayende.com/blog/archive/2010/01/05/nhibernate-versus.-entity-framework-4..aspx

If .Internet 3.5 or earlier, choose NHibernate.

http://stackoverflow.com/questions/1238972/selecting-database-and-orm-for-a-internet-project

http://stackoverflow.com/questions/567304/which-orm-tool-should-i-use-for-internet-development

http://stackoverflow.com/questions/557948/simplest-to-learn-and-use-internet-orm-framework

http://stackoverflow.com/questions/550929/some-suggestions-on-which-internet-orm-to-look-at-learning

http://stackoverflow.com/questions/474973/best-orm-tool

http://stackoverflow.com/questions/380620/what-object-mapper-solution-would-you-recommend-for-internet

http://stackoverflow.com/questions/249550/what-orm-frameworks-for-internet-do-you-like-best

http://stackoverflow.com/questions/206197/best-free-orm-tools-to-use-with-internet-2--3-5

http://stackoverflow.com/questions/132676/which-orm-for-internet-would-you-recommend

After September 04, 2009:

http://stackoverflow.com/questions/1381916/or-mapping-tool

http://stackoverflow.com/questions/1443846/o-rm-choice-not-reliant-on-linq

http://stackoverflow.com/questions/1469761/nhibernate-versus-entity-framework-versus-something-better

http://stackoverflow.com/questions/1470787/how-to-choose-an-object-relational-mapping-for-internet

Nevertheless, things change. Since NHibernate supports Linq, I believe NHibernate may be the obvious choice within the large most of situations. For an extended and fairly current analysis, you can look at this:

.Internet and ORM - Choices, choices

My preference is LLBLGenPro - a very great ORM that simply works like you'd expect. It is not according to configuration like entity framework or nhibernate, it creates your DAL according to your db (with much versatility through their tools).

http://world wide web.llblgen.com/defaultgeneric.aspx

LINQ2SQL is probobly simplest to make use of. Entity Framework provides great extensability and also the future release will contain a lot of enhancements.

One key rule for performance: write code that's simple to maintain, read and distribute whether it's to slow - optimize!

I believe the difference in performance between your ORMs today is bareley noteworthy, which means you should pick the one which feels preferred and efficent to utilize.