I found the pb

by using SET arithabort off, I reproduce the low query

in my SP, I use option (keepfixed plan)

by turn off this option, my SP is faster

there are no locks or deadlocks, application timeout is set to 30 seconds

in SSMS the SP run in 1s

one more time, when I set application connexion string to "current language=english"...

1) drop and recreate SP => dont' work

2) clear all cache for this SP => don't work

3) restart SQL => don't work

4) created a new SP with a different name...

yes, it's the same pb

I don't understand, the same SP with with the same parameters timeout in profiler but not in SSMS

thanks for your answer but there is no physical reads