Hi,
I just wanted to add something here.
Every 32-bit system (which could be the hardware *or* the OS) imposes a
2GB limit. Also, even when the files are stored in gzipped format
they are
uncompressed when read into the memory and so can take up a lot more
storage. To calculate the storage requirements of a single image it is:
Nx * Ny * Nz * Nt * BPP / (1024^3) in GB bytes
where Nx, Ny, Nz, Nt is the image size and BPP is the bytes per pixel
for
the datatype used. This is 1 for unit or char, 2 for short ints, 4
for ints and
floats and 8 for doubles (it is equal to the bits per pixel divided by
8).
Also be aware that many programs generate copies of the images
internally
at some point and so you are unlikely to get many programs to work once
a single image passes the 1GB mark.
We strongly recommend people run things on 64bit machines (with a 64bit
OS) in order to avoid these issues.
All the best,
Mark
On 10 Sep 2008, at 18:33, Martin M Monti wrote:
> Matthew,
>
> one more piece of information: I just read Yi-Chin's message (Sub:
> fslmerge out of memory) and I should mention that I also run on a
> 32bit system (just like Yi-Chin). Could that indicate some problem
> with this specific fsl version and its interactions on a 32bit
> system? I ran the very same analysis on a 64bit system and it ran
> seemlessly. On the other hand, I ran successfully much heavier
> analysis on this same system before changing over to 4.1.
>
> cheers
>
> martin
>
>
> Matthew Webster wrote:
>> Flameo can have quite a large memory footprint - are you able to
>> try the analysis on a system with more RAM?
>>
>> Many Regards
>>
>> Matthew
>>
>>> Dear FSL masters,
>>>
>>> running a simple 2nd level analysis in FEAT, with only 4 feat
>>> directories feeding in and a very simple rArArA design, I seem to
>>> run into memory problems.
>>> I tried running the same design in 4.0 and get the same error, so
>>> I'm inclined to think that this has to do with the system on which
>>> I'm running the analysis rather than FSL.
>>> (It could also be the input I'm feeding it, although I didn't
>>> notice anything aextraordinary in the feat folders -- except for
>>> the fact that I had to re-run the registration with a subsequent
>>> FEAT command.)
>>>
>>> Can I please ask you to if the error below tells you anything more?
>>>
>>> cheers
>>>
>>> martin
>>>
>>>
>>> Progress Report / Log
>>>
>>> Started at Wed Sep 3 01:12:29 BST 2008
>>>
>>> ln -s ../.files .files
>>>
>>> ------------------------------------------------------------------------
>>> Higher-level stats
>>> cat ../design.lcon | awk '{ print }' > design.lcon
>>> /imaging/local/linux/bin/fsl-4.1.0/bin/flameo --
>>> cope=filtered_func_data --vc=var_filtered_func_data --
>>> dvc=tdof_filtered_func_data --mask=mask --ld=stats --dm=design.mat
>>> --cs=design.grp --tc=design.con --fc=design.fts --runmode=fe
>>>
>>> Image Exception : #99 :: Out of memory
>>>
>>>
>>>
>>> An exception has been thrown
>>> Out of memoryTrace: Gsmanager::initialise; Gsmanager::setup.
>>>
>>
>
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