I found where is a problem. One my instance is running with broker arbitrage. If I start any second instance, whitch trying use the same DLL, is a verry slow. In the manual: Brokers A and B must not use the same broker plugin Dll.
But if use other instance, must be also other Dll.
Instance 1 (ARB).... Broker A ... plugin1.dll, Broker B ... plugin2.dll Instance 2 - only one plugin - Broker C ... plugin3.dll <-- don't use the same dll like Instance 1 Instance 3 - only one plugin - Broker C ... plugin3.dll