When beginning with the Apache web-server performance, the results from the Intel Atom netbook were not different proportionally from the applicable results in our earlier code compiler comparison on the Core 2 Duo, Core i7, and Opteron 2300 systems. The LLVM 2.8 Clang compiler performance was right on par with GCC 4.5/4.6 and earlier GNU Compiler Collection releases.
The OpenSSL results were not also vastly different, except with GCC 4.5.1 the performance had dropped compared to GCC 4.4.5. Fortunately, this regression appears to be addressed with GCC 4.6 at least in the 2010-11-20 development snapshot.
The traditional DES encryption performance with John The Ripper was effectively the same between the five tested GCC releases and the most recent LLVM/Clang version.
The MD5 performance with John The Ripper is also uninteresting with there not being much of a difference between GCC releases and LLVM's Clang is now running on par with this mature open-source compiler.