Initial tests with the binary data transportation for OPC UA show that Classic OPC (based on DCOM) is faster for small messages, while OPC UA is faster for large messages. Nevertheless, context is most important. Both Classic OPC and OPC UA can transfer tens of thousands of values per second, whereas most control systems are unable to keep up with a fraction of this data transfer rate. Consequently, OPC UA is not expected to add another bottleneck to the communication system; just as classic OPC (which was OPC before Unified Architecture) does not add a communication bottleneck today.