[Eeglablist] memory problems when reading in 128 channels Biosemi data

[Toby Fernsler]

Hi Miriam,
    How large is the file you are loading and how much total memory does 
your computer have?  The memory failure sounds odd in the sense that 
Matlab is usually good about eating up all available memory, as needed.  
On Linux and Mac it makes good use of the disk cache as well, I don't 
know remember how it works on Windows. 
    One odd issue that Matlab has is memory fragmentation: any Matlab 
variable must be loaded in a contiguous block of memory.  So even if you 
have 2GB available, you may not be able to load a 1GB file if they're 
all in chunks smaller than 1GB.  Matlab fragments its working RAM as it 
works, and has no other means of addressing this than by restarting.  
Also it may not be able to grab excessively fragmented memory, which can 
happen if the computer has been on for awhile.  So, as always, try 
rebooting.
Best,
Toby

Miriam Gade wrote:
> Hi all, 
>
> we recently bought a Biosemi EEG System and are now trying to analyse 
> a first oddball experiment  recorded with 128 channels. However, 
> EEGLAB continously reports memory failures when we try to read the 
> data in, even though the task manager under windows shows 500 MB of 
> free memory. Has anybody of you encountered the same problem? Do you 
> know how to circumvent it? thanks for any answers and greetings from 
> italy miriam 
>
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