Thanks for your reply Daniel I have a couple of question regarding what you just said: 1- Can you tell what are the appender that you know is asynchronous (in Log4J at least) 2- Why would you expect System.IO to be faster ? I understand that there is a cost (overhead) to use this kind of framework but if the appender is sending message (logging event) to a structure that it is store in memory, I expect it to be faster than an IO on disk. Am I wrong Daniel. If I recall my first post, this is exactly what I did using EIF and a specific EventSink (appender). My EventSynk only take the logging event and put it on an MSMQ and return very fast (but telling that remind me that I did not save the metrics for that one, so how fast it realy is... I'll tell you) Anyway, Thank you to both of you who reply to this post. I can't believe that in 2004 I'm still worry about logging Thanks again Michel

Hi I need a logging framework that let me log asynchronously. Do you have any suggestion ? I tried to figure out if log4net does all the logging asynchronously. Does it depend on a specific Appender or all logging is done asynchronously ? I did a test in which I log 1500 time the same string. - Log4net with FileAppender is doing it in approx. between 100 and 200 miliseconds; - Log4net with BufferingForwardingAppender combine with FileAppender is doing it in approx. 2000 miliseconds; - System.IO does it in approx. 10 miliseconds. I also tried with EIF using my own EventSink sending all request in a MSMQ queue but using EIF is not as easy to deploy as log4net so... Any suggestion would be appreciate