This week's book giveaway is in the OCPJP forum. We're giving away four copies of OCA/OCP Java SE 7 Programmer I & II Study Guide and have Kathy Sierra & Bert Bates on-line! See this thread for details.
There can be but you need to be careful. Streams can be processed either sequentially or concurrently. On small streams, processing them concurrently may take more time than doing them sequentially. You also want to make sure that a stream processed concurrently does not introduce errors. This can occur when there are “sequential” dependencies that can affect the results.
With that said, streams can result in better performance. Better yet, they are easier to build and understand than using more traditional manual multiple threading approaches.