[R] Memory limit for Windows 64bit build of R

[Uwe Ligges]

On 06.08.2012 09:34, David Winsemius wrote:
>
> On Aug 5, 2012, at 3:52 PM, Alan.X.Simpson at nab.com.au wrote:
>
>> Dear all
>>
>> I have a Windows Server 2008 R2 Enterprise machine, with 64bit R
>> installed
>> running on 2 x Quad-core Intel Xeon 5500 processor with 24GB DDR3 1066
>> Mhz
>> RAM.  I am seeking to analyse very large data sets (perhaps as much as
>> 10GB), without the addtional coding overhead of a package such as
>> bigmemory().
>
> It may depend in part on how that number is arrived at. And what you
> plan on doing with it. (Don't consider creating a dist-object.)
>>
>> My question is this - if we were to increase the RAM on the machine to
>> (say) 128GB, would this become a possibility?  I have read the
>> documentation on memory limits and it seems so, but would like some
>> additional confirmation before investing in any extra RAM.
>
> The trypical advices is you will need memory that is 3 times as large as
> a large dataset, and I find that even more headroom is needed. I have
> 32GB and my larger datasets occupy 5-6 GB and I generally have few
> problems. I had quite a few problems with 18 GB, so I think the ratio
> should be 4-5 x your 10GB object.  I predict you could get by with 64GB.
> (please send check for half the difference in cost between 64GB abd 128
> GB.)
>


10Gb objects should be fine, but note that a vector/array/matrix cannot 
exceed  2^31-1 elements, hence a 17Gb vector/matrix/array of doubles / 
reals.

Best,
Uwe Ligges