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Thread: OSX optimizations


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Permlink Replies: 3 - Last Post: Nov 21, 2015 6:29 AM Last Post By: Rudy Velthuis (... Threads: [ Previous | Next ]
bernard roussely

Posts: 106
Registered: 2/8/05
OSX optimizations  
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  Posted: Aug 6, 2015 7:26 AM
Hello,

I am finalizing a cross platform library (crunching numbers) and I started benchmarking it against Windows 32, Windows 64, Android and OSX. The code is over 30,000 lines and, remarkably enough, only 20-30 lines differ between the 3 platforms.

The code has been compiled for a "release" version, "optimized" for speed, Pentium Pro instructions on, and all debug options are off.

The processor on the Windows computer is an i7-3537U (dual core) at 2.0 Ghz and the Air Book processor is an i7-4650U at 1.7 Ghz. However the overall performance on the i7-4650U is slightly better according to PassMark (4131 vs. 3864), but these figures may not be relevant for my tests.

The issue is the following:
- execution under OS X is on average 4 times slower than on Windows 8.1 for some algorithms that are 99,99% identical (and the code difference can't explain such a huge gap)

Is there a way I can tweak the compiler options for OS X to improve something?

Regards,

bernard
Rudy Velthuis (...


Posts: 7,731
Registered: 9/22/99
Re: OSX optimizations
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  Posted: Sep 10, 2015 4:04 PM   in response to: bernard roussely in response to: bernard roussely
bernard roussely wrote:

- execution under OS X is on average 4 times slower than on Windows
8.1 for some algorithms that are 99,99% identical (and the code
difference can't explain such a huge gap)

Is there a way I can tweak the compiler options for OS X to improve
something?

Note that the OS X compiler compiles to 32 bit only, and that some RTL
routines are only assembler-optimized for Win32, not for other
platforms.

Then there are extreme timing differences between some Posix routines
used on one and the Windows routines used on the other, and some of the
routines used in the non-Windows RTL could do with some optimization
anyway.

What kind of library is it?

--
Rudy Velthuis http://www.rvelthuis.de

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mankind."
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bernard roussely

Posts: 106
Registered: 2/8/05
Re: OSX optimizations  
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  Posted: Nov 19, 2015 10:54 AM   in response to: Rudy Velthuis (... in response to: Rudy Velthuis (...
Hi Rudy,

The library is all about cryptography.

Any chance that these POSIX routines are optimized some day?

Regards,

bernard
Rudy Velthuis (...


Posts: 7,731
Registered: 9/22/99
Re: OSX optimizations  
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  Posted: Nov 21, 2015 6:29 AM   in response to: bernard roussely in response to: bernard roussely
bernard roussely wrote:

Hi Rudy,

The library is all about cryptography.

Any chance that these POSIX routines are optimized some day?

Regards,

bernard

You'll have to ask Apple.

--
Rudy Velthuis http://www.rvelthuis.de

"A treatise upon human nature: It is not contrary to reason to
prefer the destruction of the whole world to the scratching of
my finger."
-- David Hume
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