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One of our early concerns with NIO was its raw performance, and for good reason: In it's original JDK 1.4.0 release, performance was terrible. By the 1.4.2 release, the performance had improved (in some tests) by a factor of 3:1, and you can see in the following test output that it's "only" about 3x slower than putting data into a byte array, and "only" about 4.5x slower than accessing data from a byte array. Since there should be nothing theoretically faster than accessing data from a byte array, this is impressive, right?Read Cameron Purdy in Raw NIO Performance