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Old 2008-09-05, 10:25   #364
rgiltrap
 
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Quote:
Originally Posted by davieddy View Post
0.0224 sec/iter means ten days for 40M iterations.
Please keep in mind that we were running on lower performing code prior to today so that figure has limited bearing on the DC run as a whole.
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Old 2008-09-05, 10:41   #365
T.Rex
 
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Quote:
Originally Posted by T.Rex View Post
I'll see tomorrow which FFT length is used now by Glucas. I remember I've seen several messages at the beginning saying that Glucas has increased the FFT length in order to reduce the level of error under the required limit.
As Ernst said, no way to say the FFT length. However, yes, Glucas had 4 "roundoff" errors and at the end it decided to change the FFT length:
Restarting. Changed FFT length.
T.
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Old 2008-09-05, 10:53   #366
davieddy
 
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Quote:
Originally Posted by rgiltrap View Post
Please keep in mind that we were running on lower performing code prior to today so that figure has limited bearing on the DC run as a whole.
Since 13 days have passed since the initial discovery, you can
rest assured I am bearing that in mind.
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Old 2008-09-05, 10:59   #367
davieddy
 
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Quote:
Originally Posted by T.Rex View Post
As Ernst said, no way to say the FFT length. However, yes, Glucas had 4 "roundoff" errors and at the end it decided to change the FFT length:
Restarting. Changed FFT length.
T.
That must be disappointing for you.
More power to my suggestion that 2048K is inadequate!

Last fiddled with by davieddy on 2008-09-05 at 11:33
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Old 2008-09-05, 11:41   #368
ixfd64
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Well, I hope you get that 30% speed increase working!
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Old 2008-09-05, 11:48   #369
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Quote:
Originally Posted by ixfd64 View Post
Well, I hope you get that 30% speed increase working!
???
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Old 2008-09-05, 11:53   #370
ixfd64
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See post #273.
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Old 2008-09-05, 11:58   #371
T.Rex
 
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Default 30% done

30% done on my side. Still late...
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Old 2008-09-05, 12:07   #372
davieddy
 
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Quote:
Originally Posted by ixfd64 View Post
See post #273.
Are you having difficult keeping up to the pace of posting?
I think the rate of growth of this thread is probably record-breaking.
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Old 2008-09-05, 15:34   #373
ewmayer
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Quote:
Originally Posted by T.Rex View Post
As Ernst said, no way to say the FFT length. However, yes, Glucas had 4 "roundoff" errors and at the end it decided to change the FFT length
I must say, I find that very surprising - apparently the accuracy loss from Glucas' fast-multiply-up-of-roots-of-unity-and-DWT-weights scheme is significantly more than I expected.

"And the specially modified Lamborghini blows the doors off the garage..."

Here are timings for the same 16-thread 4096K FFT running on 4 quad-cores of the Sparc VII:

[Sep 04 08:11:23] Mxxxxxxxx Iter# = 2**00000 clocks = 00:33:51.000 [ 0.0203 sec/iter] Res64: CC42FF0C3E6FDD1E AvgMaxErr = 0.000002711. MaxErr = 0.000003815
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Old 2008-09-05, 15:55   #374
Jeff Gilchrist
 
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Quote:
Originally Posted by rgiltrap View Post
As of today we have the nice new Mlucas code release working which means we have a bit more speed and a lot more reliability in terms of restart capability (just in case if anything goes pear shaped).
So Ernst, are you going to make this shiny new Mlucas code available to everyone when this is all over?

I don't have any Ferrari's or Lamborghini's in my garage, and I can't even use any special Bull Linux tricks. I'm just hoping to squeak in a finish before Tony even though I had quite a head start...
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