I tried to change kernel shared memory values, but it dont change anything.
Anybody has the same problem?
P.S. sorry for my bad english

It seemed to improve performance on one of my Debian systems.With a large number of cameras (or just a few HD cameras) you may also need to increase the size of /run (tmpfs). Editing /etc/sysctl.conf is no longer enough.
The easiest way to do this is to add the following line to /etc/fstab (where 50% is the size of /run in regards to your physical memory)
tmpfs /run tmpfs nodev,nosuid,size=50%,mode=755 0 0