Analysts and others are raising questions over Apple’s claim that its new Power Mac G5 is the world’s fastest personal computer, reports c|net. “Although Apple has won praise for the new Macs as a substantial improvement over prior machines, some have criticized the choices made in putting together the rival Dell machine for use in tests developed by the Standard Performance Evaluation Corporation (SPEC). Apple’s tests, which were conducted by third-party testing firm Veritest, used the same GCC compiler for both machines, with the Dell boxes running the Linux operating system. Critics charge that much higher benchmarks can be achieved using the Windows OS and an Intel-optimized compiler, rather than GCC.” Update: Greg Joswiak, vice president of hardware product marketing at Apple, defended his company’s performance claims in a phone interview today with Slashdot