Complex sentence: The largest Blue Gene/L installation, at LLNL, subsequently grew up to 104 racks in 2007, achieving 478 TFLOPS sustained and 596 TFLOPS peak, and held the first position in the TOP500 list for 3.5 years.
Split into simpler sentences: The largest Blue Gene/L installation, at LLNL, subsequently expanded up to 104 racks in 2007, achieving 478 TFLOPS Linpack and 596 TFLOPS peak. The LLNL BlueGene/L installation held the first position in the TOP500 list for 3.5 years.