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From: Maik Beckmann (maikbeckmann_at_[hidden])
Date: 2008-01-26 07:02:50


Am Samstag 26 Januar 2008 12:51:29 schrieb nisha kannookadan:
> > ( (127^5)*5)*8 / (1024^3)
> > =
> > 1230.78 GByte
>
> ((127^5)*5)*8 is the size in byte, which is used for all these entries,
> but why do we divide by 1024^3 and not by 10^9 to receive the memory in
> GB?

1 Kilobyte = 2^10 Bytes = 1024 Byte
1 Megabyte = 2^10 Kilobyte = 1024 Kilobyte
1 Gigabyte = 2^10 Megabyte = 1024 Megabyte

2^30 = 1024^3
<ipyhon shell>
In [11]: ((127**5)*5)*8 / (1024**3)
Out[11]: 1230.77517028898

In [12]: ((127**5)*5)*8 / (2**30)
Out[12]: 1230.77517028898
</ipython shell>

> I was able to allocate a matrix of size 140000*140000:
> matrix a(140000,140000),
> how is that possible?
> This would need 146 GB, but I acctually have only 32GB RAM.

I don't know.

> Thanks
> Nisha K

Best,
 -- Maik