Clang OpenMP Benchmarks On Linux 64-bit Against GCC

[phoronix]

Phoronix: Clang OpenMP Benchmarks On Linux 64-bit Against GCC

A few days ago I posted some LLVM Clang 3.7 vs. GCC compiler benchmarks on Linux in time for the release of LLVM 3.7. While LLVM/Clang 3.7 brings full support for OpenMP 3.1, OMP tests were omitted from the original article due to running into some issues. In this article are some reference tests for Clang OpenMP performance with the latest mainline SVN code compared to GCC.

http://www.phoronix.com/vr.php?view=22125

[nosleduc]

Thank you very much.
You solved my problem I had on MacOSX.
I was stucked with only one core
It is strange that -fopenmp=libgomp and -fopenmp=libomp give different results since libgomp.dylib is a symlink to libomp.dylib with the runtime I've downloaded

[Marc Driftmeyer]

I don't know what's the deal with FX series CPUs but I'm never pushing more than 2 out of 8 core units on the FX-8350 at 4Ghz. Two at 2.1Ghz and the other two at 1.4Ghz.

Any idea?

[wargames]

GCC FTW!

[leonmaxx]

I don't know what's the deal with FX series CPUs but I'm never pushing more than 2 out of 8 core units on the FX-8350 at 4Ghz. Two at 2.1Ghz and the other two at 1.4Ghz.
Any idea?

Seems like power supply issue, or overheating. I have the same CPU, and according to "cpupower" all cores are at 4.0GHz under load.

[chithanh]

Also in default configuration, power use will be limited to the TDP of 125 W (as reported by fam15h_power). I have to change a BIOS setting to allow more than that.

[Marc Driftmeyer]

Also in default configuration, power use will be limited to the TDP of 125 W (as reported by fam15h_power). I have to change a BIOS setting to allow more than that.

I definitely had to muck with the `optimized' Gigabyte UD3 bios settings to turn on a bunch a features I expected to be on. I am testing with performance profile and 1 core is set at 1.4Ghz and the 7 others at 4Ghz now.

[jake_lesser]

It's official, clang is crap. GCC still rules. Clang is the one that's irrelevant.

[Marc Driftmeyer]

Seems like power supply issue, or overheating. I have the same CPU, and according to "cpupower" all cores are at 4.0GHz under load.

What results are you getting? My 32GB system just seems flat on these tests.

I don't have the same SSD as Michael PLEXTOR PX-128M5Pro (1.05).

[Marc Driftmeyer]

Finally got it to work. Had to selfhost build LLVM trunk, then modify the CMakeCache.txt to include -fopenmp in the CXX/CFlags and finally built with OpenMP added under the projects path.