> Last version of firebird (classic server), windows server 2008 with 8 GO of memory (i just bought another quad core processor and
> 32 GO of memory and wait them... but i don't thing it's will resolve the problem).

Are you use x64 version of Windows and Firebird ?

> the number of client is average about 200 (so i see 200 process in task manager), in firebird conf i customize only this params :
> DefaultDbCachePages = 512 (instead of 74)
> so it's mean 200 * 512 * 4kb = 409600 kb = 400 Mb only ? so how can i use all the memory ??

You *do use* the memory. Think about OS file cache.

And remember that 32-bit OS can't effectively use more than 4GB of RAM (in reality much less).
So, ensure you use x64

> i also notice that the .lck file grow to 80 MB ! is it normal ? (average 30 Mo)

Too much i'd said...


Regards,
Vlad