Re: How Much Memory Do I Need?

[Matthias Brennwald]

Just a thought: do you really need 44.1 kHz? Can you use a (much)  
lower sampling rate to reduce the amount or memory? Apart from that,  
you might take a look at MATAA (a collection of Octave/Matlab code to  
analyse test signals using the sound card):

http://www.sourceforge.net/projects/mataa

Cheers


On 18.07.2007, at 12:44, address@hidden wrote:

> I am attempting to set up a data logging system for a research  
> experiment. (minimal budget)
>
> I am capturing about 10 minutes of data (voltage and current) via  
> the sound card using Audacity.
>
> I then wish to process the data (very large files) using Octave.
>
> 10 minutes of one channel at 44,100 sps and 16 bits per sample  
> yields approximately 52.92 megabytes of data.  This becomes 105.84  
> megabytes for voltage and current (two channels or stereo on the  
> sound card).  Put another way,  
> 10minutesX60secondsX44100samplesX2channels = a column vector of  
> 52.92 million columns.
>
> The current system is:
> Pentium 3 866MHz 256Mbytes RAM
> Ubuntu 7.04
> Octave 2.9.9 (i486-pc-linux-gnu)
> Operator: Electrical engineer with basic Unix/Linux knowledge.
>
> Just how much storage do I need for, say a 100 million entries?   
> How do I go about allocating the biggest chunk possible for  
> Octave?  I can add  physical RAM, but probably not much more than  
> 1Gb.  Can I reduce the precision of the variables to 16 bit fixed  
> point?  How about swap space (probably slower)?
>
> Anyway, I am very impressed with Octave and the progress that has  
> been made over the past decade.
>
> Thanks in advance for your help.




-------
Matthias Brennwald
Lägernstrasse 6
CH 8037 Zürich
+41 (0)44 364 17 03
address@hidden