+- +-
Say hello if visiting :) by Gecko
11 Jan 2023, 07:43:05 pm

Seti is down again by Mike
09 Aug 2017, 10:02:44 am

Some considerations regarding OpenCL MultiBeam app tuning from algorithm view by Raistmer
11 Dec 2016, 06:30:56 am

Loading APU to the limit: performance considerations by Mike
05 Nov 2016, 06:49:26 am

Better sleep on Windows - new round by Raistmer
26 Aug 2016, 02:02:31 pm

Author Topic: Possibility to split up FFT data into smaller chunks  (Read 9766 times)

Offline Vyper

  • Alpha Tester
  • Knight Templar
  • ***
  • Posts: 376
Possibility to split up FFT data into smaller chunks
« on: 05 Dec 2006, 01:31:58 am »
Does anyone here know if there is possible in a clean manner to convert a 65536 & 131072 point FFT data to only use 16384 points as a maximum at a time, or perhaps splitting them up in a 16K maximum FFT points at a time?

Kind Regards Vyper

Offline Vyper

  • Alpha Tester
  • Knight Templar
  • ***
  • Posts: 376
Re: Possibility to split up FFT data into smaller chunks
« Reply #1 on: 05 Dec 2006, 11:58:38 am »
With points i mean FFT plans, how large plans do the S@H client use..

65536 or 131072 or perhaps even more??

Someone with the knowledge, Josef.. Ben.. Heeelp  :)

Offline Josef W. Segur

  • Janitor o' the Board
  • Knight who says 'Ni!'
  • *****
  • Posts: 3112
Re: Possibility to split up FFT data into smaller chunks
« Reply #2 on: 05 Dec 2006, 02:47:12 pm »
With points i mean FFT plans, how large plans do the S@H client use..

65536 or 131072 or perhaps even more??

Someone with the knowledge, Josef.. Ben.. Heeelp  :)

131072 is the maximum in use, but that's controlled by values in the workunit header and a properly designed program should be able to do larger ones too.

All practical FFT algorithms do divide the work into smaller units and combine them for the final result. But the way it is split and recombined is not trivial. I can't go any further since I haven't studied the algorithms in detail.

One possible area you might search is the projects trying to find Mersenne primes. They use very long FFTs in a method for multiplying huge numbers, and it's likely someone in those communities has investigated using a GPU.
                                                                                Joe

Offline Vyper

  • Alpha Tester
  • Knight Templar
  • ***
  • Posts: 376
Re: Possibility to split up FFT data into smaller chunks
« Reply #3 on: 06 Dec 2006, 06:33:26 am »
Hans found an interesting article here at FFTW's homepage about splitting FFT chunks..

That approach may be useable for him (us), getting back with response l8r..

http://www.fftw.org/pruned.html

Btw, thanks Josef for your concern.. Much appreciated with theoretical input to get past stuck problems..


Kind Regards Vyper

Nebby

  • Guest
Re: Possibility to split up FFT data into smaller chunks
« Reply #4 on: 05 Mar 2007, 08:28:04 pm »
According to the link below, nVidia plans on increasing it's FFT size restrictions in a later release of CUDA.

http://forums.nvidia.com/lofiversion/index.php?t28384.html

 

Welcome, Guest.
Please login or register.
 
 
 
Forgot your password?
Members
Total Members: 97
Latest: ToeBee
New This Month: 0
New This Week: 0
New Today: 0
Stats
Total Posts: 59559
Total Topics: 1672
Most Online Today: 257
Most Online Ever: 983
(20 Jan 2020, 03:17:55 pm)
Users Online
Members: 0
Guests: 203
Total: 203
Powered by EzPortal