GCC & LLVM Clang Performance On The Intel Atom

A few weeks ago there were benchmarks of GCC, LLVM-GCC, DragonEgg, and Clang. In this compiler performance comparison the releases of GCC 4.2, 4.3, 4.4, 4.5, and a 4.6 development snapshot were benchmarked. On the LLVM side there was LLVM-GCC 4.2, DragonEgg with GCC 4.5 and LLVM 2.8, and then Clang with LLVM 2.8. This combination of eight open-source compilers were tested on three distinct Intel and AMD systems (even a 12-thread Core i7 Gulftown), but all of which were 64-bit capable and contained relatively high-end processors from their respective series. To complement this earlier article, available now are some new GCC/LLVM benchmarks but this time an older Intel Atom CPU was used to look at the 32-bit compiler performance on a slower, low-power netbook.

This round of Linux compiler testing is quite similar to the earlier article from November but there are a few differences. Among the differences, the latest point release in each major GCC release was used (i.e. GCC 4.4.5 versus GCC 4.4.0). This led the GCC benchmarks on the Intel Atom netbook to be GCC 4.2.4, 4.3.5, 4.4.5, 4.5.1, and 4.6.0-20101120. Though as the Intel Atom N270 processor is significantly slower than an Intel Core i7 970, AMD Opteron workstation CPUs, and other similar x86/x86_64 processors, for this article we left out from re-testing LLVM-GCC and DragonEgg, due to the significant time it takes to build each compiler, re-build all of the tests, and then finally execute the tests. Granted, it is all automated via the Phoronix Test Suite and Phoromatic, but the focus of this article is going to be on the GCC and LLVM Clang performance on the original Intel Atom since those are the two most popular compiler choices at this time.

This Intel Atom netbook was the Samsung NC10 with an Intel N270 1.60GHz processor, Intel 945GME + ICH7-M motherboard, 2GB of system memory, a 32GB OCZ Core SSD, and Intel 945 integrated graphics. On the software side it was running Ubuntu 10.04.1 LTS with the Linux 2.6.32 i686 kernel, GNOME 2.30.2, X.Org Server 1.7.6, xf86-video-intel 2.9.1, and an EXT4 file-system.

The tests from the Phoronix Test Suite included Apache, OpenSSL, John The Ripper, BYTE Unix Benchmark, C-Ray, Himeno, MAFFT, HMMer, 7-Zip, LAME MP3, FLAC, x264, and GraphicsMagick. Lastly, the Phoronix Test Suite 3.0 "Iveland" code also timed the compilation of the Apache web-server and ImageMagick.