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#1 2003-03-18 7:38 pm
- MajorMatt
- Member
- Registered: 2000-02-04
- Posts: 1152
Is it true seti@home doesnt use altivec?
Is it true seti@home doesnt use altivec?
Is this the reason why performance is proportional to mhz?
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#2 2003-03-18 10:50 pm
- kamizuno
- Poking you with a stick
- From: Smileytown
- Registered: 1999-07-13
- Posts: 1881
Re: Is it true seti@home doesnt use altivec?
Yeah, as far as anybody knows it doesn't use altivec. I read once that the reason they don't use altivec is because they have so many people crunching numbers for them that they actually don't need to optimize the software on any one platform.Or so I read 
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#3 2003-03-19 6:15 pm
- dvpierce
- Negusa Negest
- Moderator
- From: Minneapolis, MN
- Registered: 1999-08-30
- Posts: 16888
Re: Is it true seti@home doesnt use altivec?
That's correct.
As near as I can tell, SETI is almost entirely dependent on MHz, regardless of CPU type of OS. Using the GUI client tacks an extra 33% or so onto the crunch time, but running the CLI or the GUI with the window rolled up (OS 9), I've seen my crunch times scale almost perfectly with raw CPU MHz (or GHz)
-dvpierce
"Now commences the process of cutting off the head, which generally takes from an hour to an hour and a half by an expert workman with a sharp blade." -Reuben Delano, Wanderings and Adventures
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#4 2003-03-19 6:52 pm
- danielb0101
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- Registered: 2001-09-29
- Posts: 2161
Re: Is it true seti@home doesnt use altivec?
If I remember correctly none of the clients are optimized for any CPU. No MMX, no SSE, no Altivec, etc. But, I could be wrong.
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#5 2003-04-18 1:02 am
- Cory5412
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- Registered: 2003-04-13
- Posts: 159
Re: Is it true seti@home doesnt use altivec?
does this mean it might be possible for SETI to run on a 68k with BSD or linux?
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#6 2003-04-21 3:51 pm
- dvpierce
- Negusa Negest
- Moderator
- From: Minneapolis, MN
- Registered: 1999-08-30
- Posts: 16888
Re: Is it true seti@home doesnt use altivec?
does this mean it might be possible for SETI to run on a 68k with BSD or linux?
No.
Softwar has to be recompiled, notonly for different OSes, but to support different CPUs.
http://setiathome.ssl.berkeley.edu/unix.html
If you look at the above page, you will find that various available version of the CLI S@H client are keyed for both CPU type and OS, which is why there is one version for NetBSD on PowerPC computers, and another version for NetBSD on i386 comatibles.
Besides, a 33 MHz 68040 would need (on average) over 200 hours to crunch a WU, and the system considers the WU 'lost' if it's not returned within 168 hours, so you're not helping the project any.
"Now commences the process of cutting off the head, which generally takes from an hour to an hour and a half by an expert workman with a sharp blade." -Reuben Delano, Wanderings and Adventures
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#7 2003-04-25 8:15 pm
- jkahless
- Member
- From: Right in front of you.
- Registered: 2002-01-05
- Posts: 9379
Re: Is it true seti@home doesnt use altivec?
Folding @ Home now supports altivec. 
//donns flame retardant suit//
But that sucks. I wanted to have a cluster of old mac running seti. Something like 200 of them so that it would be equal to a modern computer.
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#8 2003-04-29 9:33 am
- dvpierce
- Negusa Negest
- Moderator
- From: Minneapolis, MN
- Registered: 1999-08-30
- Posts: 16888
Re: Is it true seti@home doesnt use altivec?
But that sucks. I wanted to have a cluster of old mac running seti. Something like 200 of them so that it would be equal to a modern computer.
At 100-200w a pop? it's your electricity bill. Give me a fast Dual-CPU PC as a SETI cruncher any day.
"Now commences the process of cutting off the head, which generally takes from an hour to an hour and a half by an expert workman with a sharp blade." -Reuben Delano, Wanderings and Adventures
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