LinuxDNA Supercharges Linux with the Intel C/C++ Compiler (Linux Journal)

Posted Feb 27, 2009 21:27 UTC (Fri) by flewellyn (subscriber, #5047)
In reply to: LinuxDNA Supercharges Linux with the Intel C/C++ Compiler (Linux Journal) by SLi
Parent article: LinuxDNA Supercharges Linux with the Intel C/C++ Compiler (Linux Journal)

That's been my experience as well. The last comprehensive speed test between the two, which I read three years ago (can't remember the URL), had GCC outperforming ICC in terms of compiled code performance on some benchmarks, ICC showing better performance on others, and in the remainder, the difference was too small to be significant. In some cases, the difference depended on which compiler options were selected; using -fomit-frame-pointer gave GCC a significant boost, for instance.

Overall, there was no clear winner in terms of performance, and GCC has enough other advantages (portability, openness, compiles more languages) to make it an attractive solution.

LinuxDNA Supercharges Linux with the Intel C/C++ Compiler (Linux Journal)

Posted Feb 27, 2009 21:38 UTC (Fri) by dlang (guest, #313) [Link]

not to mention that many aspects of the kernel are very carefully tuned to produce very good code.

as a result I wouldn't expect that big a difference compared to a tailored kernel with gcc. if you compare the generic disto kernels to one tailored you have a different story. just taloring the kernel and using gcc will make a significant difference (easily 10% or more depending on the cpu)

LinuxDNA Supercharges Linux with the Intel C/C++ Compiler (Linux Journal)

Posted Feb 28, 2009 4:52 UTC (Sat) by dkite (guest, #4577) [Link] (8 responses)

Wasn't the advantage with icc that it could optimize code for the Intel
processor that for the life of me I can't remember the name of?

Derek

LinuxDNA Supercharges Linux with the Intel C/C++ Compiler (Linux Journal)

Posted Feb 28, 2009 13:48 UTC (Sat) by nix (subscriber, #2304) [Link] (7 responses)

IA64?

Call me when you see one of them. It might be easier finding a working
crystal ball, or a gate to Fairyland. (I've never even sshed to one, or
been employed by anyone who has one.)

LinuxDNA Supercharges Linux with the Intel C/C++ Compiler (Linux Journal)

Posted Feb 28, 2009 18:08 UTC (Sat) by Trelane (subscriber, #56877) [Link] (3 responses)

I have one of them that I'd rather like to use. It's getting a little old in the tooth, though. From what I understand, their floating-point performance is superb, which is critical for my uses.

LinuxDNA Supercharges Linux with the Intel C/C++ Compiler (Linux Journal)

Posted Feb 28, 2009 18:11 UTC (Sat) by Trelane (subscriber, #56877) [Link] (2 responses)

I should also mention that the main IA64 use case anymore, i.e. floating point, makes the kernel more or less irrelevant. The main bottlenecks in heavy floating-point code aren't going to be in the kernel.

The other reason I'm interested in the intel compilers, mkl, and ipp is that they support the atom architecture, which gcc doesn't yet.

LinuxDNA Supercharges Linux with the Intel C/C++ Compiler (Linux Journal)

Posted Mar 1, 2009 9:57 UTC (Sun) by epa (subscriber, #39769) [Link] (1 responses)

Does anyone have meaningful performance comparisons of Itanic versus x86_64 for integer performance? (e.g. the classic Linux kernel compile benchmark - for a fair test, one of the two systems would have to cross-compile.)

IA-64 vs AMD64 integer performance

Posted Mar 6, 2009 17:54 UTC (Fri) by anton (subscriber, #25547) [Link]

SPECint is usually considered a good integer benchmark. Here are some results:

                                                   Result Baseline
HP Integrity rx2660 (1.66GHz/18MB Dual-Core Itanium) 17.0     15.7
ASUS P6T WS PRO (Intel Core i7-965)                  35.2     31.5

LinuxDNA Supercharges Linux with the Intel C/C++ Compiler (Linux Journal)

Posted Mar 1, 2009 15:46 UTC (Sun) by oseemann (guest, #6687) [Link]

I also was surprised when I learned last year that a customer of ours bought an Itanium machine as his OLTP host (POS terminal front end processor). Thought they were long dead. The Tandem OS running on the machine(s) had some peculiar limitations, e.g. only upper-case file names and max 8 chars. Who would have thought such systems are deployed in 2008!

LinuxDNA Supercharges Linux with the Intel C/C++ Compiler (Linux Journal)

Posted Mar 2, 2009 21:04 UTC (Mon) by dlapine (guest, #7358) [Link]

I have about 1800 Itaniums running in my linux cluster (dual socket). 1700 running user jobs and about 100 for filesystem serving.

http://www.ncsa.uiuc.edu/UserInfo/Resources/Hardware/TGIA...

We have over 1024 of them running on our SGI Altix machines.

http://www.ncsa.uiuc.edu/UserInfo/Resources/Hardware/SGIA...

The itaniums are good for scientific computing.

SDSC had some as did Caltech and Argonne Nat'l Labs.

Given that these were released as early as 2002, they don't have energy saving features.

As for performance, Our Mercury cluster was fairly comparable to our old Xeon cluster:

http://www.ncsa.uiuc.edu/UserInfo/Resources/Hardware/Xeon...

Given that they had about 1250 servers versus the 872 on Mercury and the
top500 numbers were about 10TF versus the 7.2TF Mercury had.

LinuxDNA Supercharges Linux with the Intel C/C++ Compiler (Linux Journal)

Posted Mar 3, 2009 16:09 UTC (Tue) by zlynx (guest, #2285) [Link]

I've got two.

GCC being superior?

Posted Feb 28, 2009 16:33 UTC (Sat) by ikm (guest, #493) [Link]

Are there any links to back this up? Would be wonderful news.

LinuxDNA Supercharges Linux with the Intel C/C++ Compiler (Linux Journal)

Posted Mar 2, 2009 6:44 UTC (Mon) by muwlgr (guest, #35359) [Link]

This one is a comparison I remember -

http://www.coyotegulch.com/reviews/linux_compilers/index....