Re: For those wondering "Why Playstation 3s?" in http://www.dslreports.com/forum/r21674120 en Tue, 24 Nov 2009 23:30:10 EDT Tue, 24 Nov 2009 23:30:10 EDT Re: For those wondering "Why Playstation 3s?" http://www.dslreports.com/forum/remark,21674120 Kearnstd : PS3s really are being used in ways that Sony never intended lol. how long till DARPA builds a supercomputer of 5000 PS3 CPUs lol.
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[65 Arcanist]Filan(High Elf) Zone: Broadband Reports]]> http://www.dslreports.com/forum/remark,21674120 Sat, 03 Jan 2009 09:30:49 EDT Re: For those wondering "Why Playstation 3s?" http://www.dslreports.com/forum/remark,21671048 Steve :
said by TSI Gabe See Profile :

No Actually removing a printf simply displaying the value being calculated completely removed the md5 function from the code.
The compiler did what it was supposed to do: if you were calling a function that had no side effects, it knew that it could eliminate the call without having any effect on correct operation. It was right.

Benchmarking is a known science; calling your operation in a way that insists on a side effect (as I'm sure you found) lets you get the effect you want.

Steve
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Stephen J. Friedl | Unix Wizard | Microsoft Security MVP | Orange County, California USA | my web site]]> http://www.dslreports.com/forum/remark,21671048 Fri, 02 Jan 2009 16:28:03 EDT Re: For those wondering "Why Playstation 3s?" http://www.dslreports.com/forum/remark,21670956 TSI Gabe : No Actually removing a printf simply displaying the value being calculated completely removed the md5 function from the code.]]> http://www.dslreports.com/forum/remark,21670956 Fri, 02 Jan 2009 16:09:54 EDT Re: For those wondering "Why Playstation 3s?" http://www.dslreports.com/forum/remark,21670584 Steve :
said by TSI Gabe See Profile :

That was the C compiler optimizing my code into doing nothing quite literally. Sometimes those C optimizations don't really help...
It's far more likely that your optimizer found a bug in your code than you found a bug in the optimizer.

The problem with compilers is that they do exactly what you ask them too bad women and children won't follow that example ;-)

Steve
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Stephen J. Friedl | Unix Wizard | Microsoft Security MVP | Orange County, California USA | my web site]]> http://www.dslreports.com/forum/remark,21670584 Fri, 02 Jan 2009 14:59:09 EDT Re: For those wondering "Why Playstation 3s?" http://www.dslreports.com/forum/remark,21670558 TSI Gabe : That was the C compiler optimizing my code into doing nothing quite literally. Sometimes those C optimizations don't really help...]]> http://www.dslreports.com/forum/remark,21670558 Fri, 02 Jan 2009 14:53:54 EDT Re: For those wondering "Why Playstation 3s?" http://www.dslreports.com/forum/remark,21670487 beaups : lol I was just wondering the same thing]]> http://www.dslreports.com/forum/remark,21670487 Fri, 02 Jan 2009 14:36:57 EDT Re: For those wondering "Why Playstation 3s?" http://www.dslreports.com/forum/remark,21670037 Steve :
said by TSI Gabe See Profile :

Yeah I've coded an MD5 algo myself for the PS3 and it does 80 million hashes per second.
What ever happened to 30 billion hashes per second?
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Stephen J. Friedl | Unix Wizard | Microsoft Security MVP | Orange County, California USA | my web site]]> http://www.dslreports.com/forum/remark,21670037 Fri, 02 Jan 2009 13:03:17 EDT Re: For those wondering "Why Playstation 3s?" http://www.dslreports.com/forum/remark,21669050 TSI Gabe : Yeah I've coded an MD5 algo myself for the PS3 and it does 80 million hashes per second.

This may not look like a lot, but its just about as much as a very expensive Xeon server so your bang for the buck is quite real.]]> http://www.dslreports.com/forum/remark,21669050 Fri, 02 Jan 2009 09:13:14 EDT For those wondering "Why Playstation 3s?" http://www.dslreports.com/forum/remark,21669031 espaeth : There's a nice overview here: »people.csail.mit.edu/tromer/slid···rump.pdf]]> http://www.dslreports.com/forum/remark,21669031 Fri, 02 Jan 2009 09:07:56 EDT