clang O2 this is used for testing clang with O2 gcc o2: Processor: Intel Core i5-3470 @ 3.19GHz (4 Cores), Motherboard: LENOVO QiTianM4350, Chipset: Intel Xeon E3-1200 v2/3rd, Memory: 3584MB, Disk: 500GB Seagate ST500DM002-1BD14, Graphics: Intel HD 2500 (1100MHz), Audio: Realtek ALC662 rev3, Network: Realtek RTL8111/8168/8411 OS: Ubuntu 14.04, Kernel: 3.13.0-32-generic (x86_64), Desktop: Unity 7.2.2, Display Server: X Server 1.15.1, Display Driver: intel 2.99.910, OpenGL: 3.3 Mesa 10.1.3, Compiler: GCC 4.6.4 + Clang 3.3 + LLVM 3.3, File-System: ext4, Screen Resolution: 1440x900, System Layer: Xen 4.4.0 Hypervisor gcc o3: Processor: Intel Core i5-3470 @ 3.19GHz (4 Cores), Motherboard: LENOVO QiTianM4350, Chipset: Intel Xeon E3-1200 v2/3rd, Memory: 3584MB, Disk: 500GB Seagate ST500DM002-1BD14, Graphics: Intel HD 2500 (1100MHz), Audio: Realtek ALC662 rev3, Network: Realtek RTL8111/8168/8411 OS: Ubuntu 14.04, Kernel: 3.13.0-32-generic (x86_64), Desktop: Unity 7.2.2, Display Server: X Server 1.15.1, Display Driver: intel 2.99.910, OpenGL: 3.3 Mesa 10.1.3, Compiler: GCC 4.6.4 + Clang 3.3 + LLVM 3.3, File-System: ext4, Screen Resolution: 1440x900, System Layer: Xen 4.4.0 Hypervisor clang o3: Processor: Intel Core i5-3470 @ 3.19GHz (4 Cores), Motherboard: LENOVO QiTianM4350, Chipset: Intel Xeon E3-1200 v2/3rd, Memory: 3584MB, Disk: 500GB Seagate ST500DM002-1BD14, Graphics: Intel HD 2500 (1100MHz), Audio: Realtek ALC662 rev3, Network: Realtek RTL8111/8168/8411 OS: Ubuntu 14.04, Kernel: 3.13.0-32-generic (x86_64), Desktop: Unity 7.2.2, Display Server: X Server 1.15.1, Display Driver: intel 2.99.910, OpenGL: 3.3 Mesa 10.1.3, Compiler: Clang 3.3 + GCC 4.6.4 + LLVM 3.3, File-System: ext4, Screen Resolution: 1440x900, System Layer: Xen 4.4.0 Hypervisor clang o2: Processor: Intel Core i5-3470 @ 3.19GHz (4 Cores), Motherboard: LENOVO QiTianM4350, Chipset: Intel Xeon E3-1200 v2/3rd, Memory: 3584MB, Disk: 500GB Seagate ST500DM002-1BD14, Graphics: Intel HD 2500 (1100MHz), Audio: Realtek ALC662 rev3, Network: Realtek RTL8111/8168/8411 OS: Ubuntu 14.04, Kernel: 3.13.0-32-generic (x86_64), Desktop: Unity 7.2.2, Display Server: X Server 1.15.1, Display Driver: intel 2.99.910, OpenGL: 3.3 Mesa 10.1.3, Compiler: Clang 3.3 + GCC 4.6.4 + LLVM 3.3, File-System: ext4, Screen Resolution: 1440x900, System Layer: Xen 4.4.0 Hypervisor Timed HMMer Search 2.3.2 Pfam Database Search Seconds < Lower Is Better gcc o2 ... 17.67 |============================================================ gcc o3 ... 17.70 |============================================================ clang o3 . 17.90 |============================================================= clang o2 . 17.66 |============================================================ Gcrypt Library 1.4.4 CAMELLIA256-ECB Cipher Microseconds < Lower Is Better gcc o2 ... 2370 |============================================================== gcc o3 ... 2360 |============================================================== clang o3 . 2350 |============================================================= clang o2 . 2340 |============================================================= John The Ripper 1.8.0 Test: Blowfish Real C/S > Higher Is Better gcc o2 ... 3425 |=========================================================== gcc o3 ... 3547 |============================================================== clang o3 . 3473 |============================================================ clang o2 . 3571 |============================================================== x264 2014-01-09 H.264 Video Encoding Frames Per Second > Higher Is Better gcc o2 ... 110.32 |=========================================================== gcc o3 ... 106.59 |========================================================= clang o3 . 111.47 |============================================================ clang o2 . 109.54 |=========================================================== GraphicsMagick 1.3.19 Operation: Sharpen Iterations Per Minute > Higher Is Better gcc o2 ... 46 |================================================================ gcc o3 ... 45 |=============================================================== clang o3 . 46 |================================================================ clang o2 . 46 |================================================================ GraphicsMagick 1.3.19 Operation: Resizing Iterations Per Minute > Higher Is Better gcc o2 ... 114 |=============================================================== gcc o3 ... 113 |============================================================== clang o3 . 114 |=============================================================== clang o2 . 112 |============================================================== GraphicsMagick 1.3.19 Operation: HWB Color Space Iterations Per Minute > Higher Is Better gcc o2 ... 151 |=============================================================== gcc o3 ... 146 |============================================================= clang o3 . 150 |=============================================================== clang o2 . 149 |============================================================== 7-Zip Compression 9.20.1 Compress Speed Test MIPS > Higher Is Better gcc o2 ... 12478 |============================================================ gcc o3 ... 12293 |============================================================ clang o3 . 12461 |============================================================ clang o2 . 12591 |============================================================= Timed Apache Compilation 2.4.7 Time To Compile Seconds < Lower Is Better gcc o2 ... 45.62 |========================================================== gcc o3 ... 47.98 |============================================================= clang o3 . 43.08 |======================================================= clang o2 . 42.33 |====================================================== Timed ImageMagick Compilation 6.8.1-10 Time To Compile Seconds < Lower Is Better gcc o2 ... 77.12 |=========================== gcc o3 ... 171.80 |============================================================ clang o3 . 58.60 |==================== clang o2 . 57.56 |==================== Timed PHP Compilation 5.2.9 Time To Compile Seconds < Lower Is Better gcc o2 ... 45.05 |=========================================================== gcc o3 ... 46.34 |============================================================= clang o3 . 39.36 |==================================================== clang o2 . 37.41 |================================================= C-Ray 1.1 Total Time Seconds < Lower Is Better gcc o2 ... 45.15 |============================================================= gcc o3 ... 44.85 |============================================================= clang o3 . 44.89 |============================================================= clang o2 . 44.95 |============================================================= Bullet Physics Engine 2.81 Test: Raytests Seconds < Lower Is Better gcc o2 ... 4.05 |============================================================== gcc o3 ... 4.04 |============================================================== clang o3 . 4.04 |============================================================== clang o2 . 4.05 |============================================================== Bullet Physics Engine 2.81 Test: 3000 Fall Seconds < Lower Is Better gcc o2 ... 6.00 |============================================================= gcc o3 ... 6.12 |============================================================== clang o3 . 6.04 |============================================================= clang o2 . 5.99 |============================================================= Bullet Physics Engine 2.81 Test: 1000 Stack Seconds < Lower Is Better gcc o2 ... 7.06 |============================================================= gcc o3 ... 7.12 |============================================================== clang o3 . 7.00 |============================================================= clang o2 . 7.05 |============================================================= Bullet Physics Engine 2.81 Test: 1000 Convex Seconds < Lower Is Better gcc o2 ... 6.57 |============================================================== gcc o3 ... 6.51 |============================================================= clang o3 . 6.53 |============================================================== clang o2 . 6.53 |============================================================== Bullet Physics Engine 2.81 Test: Convex Trimesh Seconds < Lower Is Better gcc o2 ... 1.56 |============================================================== gcc o3 ... 1.56 |============================================================== clang o3 . 1.56 |============================================================== clang o2 . 1.56 |============================================================== LAME MP3 Encoding 3.99.3 WAV To MP3 Seconds < Lower Is Better gcc o2 ... 14.31 |============================================================= gcc o3 ... 14.31 |============================================================= clang o3 . 14.33 |============================================================= clang o2 . 14.38 |============================================================= OpenSSL 1.0.1g RSA 4096-bit Performance Signs Per Second > Higher Is Better gcc o2 ... 448.13 |============================================================ gcc o3 ... 450.90 |============================================================ clang o3 . 450.63 |============================================================ clang o2 . 450.40 |============================================================ Apache Benchmark 2.4.7 Static Web Page Serving Requests Per Second > Higher Is Better gcc o2 ... 9517.13 |========================================================= gcc o3 ... 9651.14 |========================================================= clang o3 . 9905.39 |=========================================================== clang o2 . 9590.52 |=========================================================