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i_wolf

macrumors regular
Original poster
Jul 17, 2002
136
0
maybe they were a bit modest about revealing the full story.....
IBM's latest XLF compilers released for free for G5 show a 210% improvment on floating point scaler over GCC optimized -03 code, 70% improvement on vector with altivec over GCC optimized -03 and about 30 -40% better on integer over the GCC3.3 optimized -O3
http://arstechnica.infopop.net/Open...=4250963285&p=1


Fixed peterh's formatting (XL improvement over Absoft and GCC 3.3):


Type of Code G4 G5
Scalar +70% +210%
Vector +40% +70%
If this holds that places his 2.0GHz G5 (single)=254 at 787

Note also that the P4 2.66 is 255.


Inicdentally this is an improvement ONLY from recompiling the code! :O
Hmm.... I can't wait till a newly compiled SPEC comes out compiled with this processor. It seams the doubters have been proven wrong, the performance we have seen so far is only the tip of the iceberg.
Incidentally all apple did when compiling for the SPEC marks was compile with GCC 3.3 with -O3. They themselves said that the GCC didn't do any favours what so ever for the G5 and that it wasn't really producing code that took full advantage of the chip. Those IBM compiler results would seam to definately prove them right.
For those of you that will wonder how apple will squeeze 200% + performance improvement out of OSX 10.4 , my money is on them recompiling OS X with IBM's compiler!
 

Sun Baked

macrumors G5
May 19, 2002
14,937
157
Re: are apples spec results flawed.......

Originally posted by i_wolf
...For those of you that will wonder how apple will squeeze 200% + performance improvement out of OSX 10.4 , my money is on them recompiling OS X with IBM's compiler!
Probably not, they are probably more interested in continuing with GCC and using the same in-house compiler that they offer to their developers.

Plenty of compiler projects have come and gone, and Apple seems to be pushing people to transition away from CodeWarrior to XCode now.

http://developer.apple.com/tools/switchtoxcode.html

And since GCC is one of the standards groups they are working with, it's doubtful that they'll switch to IBMs compiler.

Some have said that the IBM developer tools may be rather pricey, compared to the $129 dollars you spend on Apple's OS & Developer Tools.

There were hints that Apple/IBM were working to build a better PPC 970 model for the GCC compiler.
 
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