Hi Ananth
> There are two questions in this post
>
> FIRSTI have recently migrated to SPM and have been preprocessing different data
> samples. I have noticed that some steps in preprocessing takes as long as 8
> hours to run, especially the coregistration. Other steps such as
> Normalization take 2 hours to run.
> I have a fairly fast processor: Intel Pentium D dual core CPU 3.00GHz with
> 504MB of RAM. I am running WinXP Pro SP2.
> I am working with fMRI data with 35 slices and 200 volumes. I have also
> noticed a processor utilization of upto 50% during this time. During
> coregistration step, there is less than 5% utilization.
> Is this normal? If not, how can I increase speed? I looked under defaults
> button, but there wasn't anything I could notice.
>
yeh SPM is slower than others but others are not as good :-) there
is actually a paper on this but I can't remember the ref ..
anyway it seems abnormally long ; I think it depends the image
dimensions, i.e. if you do have lot of black around (large FOV) remove
it, this should help -
and second, run matlab without the java machine (on windows, start, run
and type matlab -nojvm) - last because matlab and windows aren't good
friends if you can try on mac or linux
> SECOND
> I don't like working with two files for every volume. I find it cumbersome.
> Is there an option to deal with all volumes in the same file? I looked under
> the defaults button for this as well, but couldn't find one. If so, how can
> I turn that option on?
>
in spm_defaults, you set to work with 4D matrices
hope this will help
Cyril
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