Questions, comments and problems on new Fermi LAT gamma-ray pulsar search

WolfK
WolfK
Joined: 25 May 08
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CPU time compared,

CPU time compared, Gravitational Wave S6 GC search v1.01 (SSE2)
versus Gamma-ray pulsar search #1 v0.23
Intel Core 2 Duo E8200, overclocked, running at 3 GHz.
My ratio is 1.54, based on 18 Gravitationals an 9 Gammas.

Mad_Max
Mad_Max
Joined: 2 Jan 10
Posts: 136
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Nice speedup in last version!

Nice speedup in last version!
My CPU time on LAT WUs drops from ~50.5k sec to ~31k sec (63% faster!).
Ratio between Fermi LAT and GW S6 now is 1.48:1
With new credit amount (337 vs 251) it give near parity in credit/hour(day).

MarkJ
MarkJ
Joined: 28 Feb 08
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There was a mention that the

There was a mention that the project were working on getting a cuda app going for these gamma-ray tasks, although I can't recall the exact message now. Is there any progress on that front?

Snagletooth
Snagletooth
Joined: 22 Feb 07
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Are there any more efforts

Are there any more efforts being made to reduce the cross-validation problems? My poor mac has had dismal luck with, I think, six out of seven eventually being deemed invalid. Should I expect 10% invalids over the long term (just hang in there) or is my machine really producing something significantly different from the others? I can't help but wonder if it wouldn't be a better use of everyone's resources if I uncheck the gamma-ray search in my preferences. Any advice?

Best,
Snags

Edward Lim
Edward Lim
Joined: 13 Aug 10
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I wouldn't pin my hopes on

I wouldn't pin my hopes on waiting for a fix. There aren't enough Mac participants to warrant it.
I unchecked the box after having lost hundreds of hours of computer time. It's a disservice to yourself and the overall project goals to end up with validation errors.

Bernd Machenschalk
Bernd Machenschalk
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All these issues are still on

All these issues are still on my todo list; I just didn't find the time to work on these in the past few weeks due to more urgent matters. I hope to get back to working on the FGRP app in the next few days.

At least I wrote a small tool that quantifies the cross-application validation rate, allowing me to measure success in that area. However I suspect the problem to be in some (barycentering) library about which I don't have much knowledge or control.

As for a GPU version: I won't have much time to spend on a CUDA version, but go directly for OpenCL instead. This will, however, require some support from the BOINC Client (and possibly server) side. We are actively developing this with the BOINC devs, but is also still work in progress and not finished yet.

BM

BM

Ver Greeneyes
Ver Greeneyes
Joined: 26 Mar 09
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RE: However I suspect the

Quote:
However I suspect the problem to be in some (barycentering) library about which I don't have much knowledge or control.


Who maintains the library? I would assume that they don't want their library to produce different results on MacOS either :) Alternatively, if the library is old and no longer being maintained, how hard do you think the functionality would be to reproduce?

Bernd Machenschalk
Bernd Machenschalk
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RE: RE: However I suspect

Quote:
Quote:
However I suspect the problem to be in some (barycentering) library about which I don't have much knowledge or control.

Who maintains the library? I would assume that they don't want their library to produce different results on MacOS either :) Alternatively, if the library is old and no longer being maintained, how hard do you think the functionality would be to reproduce?

The problem with that library is that it uses "long double", which is not a standard C datatype and is handled differently depending on compiler, compiler version, platform and options used.

BM

BM

Snagletooth
Snagletooth
Joined: 22 Feb 07
Posts: 418
Credit: 2,855,978
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RE: All these issues are

Quote:

All these issues are still on my todo list; I just didn't find the time to work on these in the past few weeks due to more urgent matters. I hope to get back to working on the FGRP app in the next few days.

At least I wrote a small tool that quantifies the cross-application validation rate, allowing me to measure success in that area. However I suspect the problem to be in some (barycentering) library about which I don't have much knowledge or control.

As for a GPU version: I won't have much time to spend on a CUDA version, but go directly for OpenCL instead. This will, however, require some support from the BOINC Client (and possibly server) side. We are actively developing this with the BOINC devs, but is also still work in progress and not finished yet.

BM

Thank you for the reply. I'll keep an eye on this thread for any further developments.

Best,
Snags

robertmiles
robertmiles
Joined: 8 Oct 09
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RE: As for a GPU version: I

Quote:

As for a GPU version: I won't have much time to spend on a CUDA version, but go directly for OpenCL instead. This will, however, require some support from the BOINC Client (and possibly server) side. We are actively developing this with the BOINC devs, but is also still work in progress and not finished yet.

BM

You might want to contact the POEM@HOME developers. They already have their application converted to OpenCL, but currently CPU only. They are also waiting for a BOINC version that can handle OpenCL GPU applications.

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