[Rd] 64 bit R for Windows

[Duncan Murdoch]

On 9/2/2005 11:59 AM, Milton Lopez wrote:
> I appreciate the update. We will consider using Linux, which leads me to
> one more question: what is the maximum RAM that R can use on each
> platform (Linux and Windows)?

On 32 bit Windows, I believe the limit is normally 2 G total for all 
user processes, but can be raised to 3 G with some work.  (If you have a 
4 G machine, the OS reserves 1 or 2 G for itself.)  R can use as much 
memory as Windows will give it, but may not be able to make large 
allocations if memory is fragmented, or reserved by other processes.

The limit under 64 bit Linux is much larger, but I don't know exactly 
what.

Duncan Murdoch
> 
> Thanks again for your prompt responses.
> 
> 
> M.
> 
> -----Original Message-----
> From: Luke Tierney [mailto:luke at stat.uiowa.edu] 
> Sent: Wednesday, August 31, 2005 6:04 PM
> To: Duncan Murdoch
> Cc: Milton Lopez; r-devel at r-project.org
> Subject: Re: [Rd] 64 bit R for Windows
> 
> On Wed, 31 Aug 2005, Duncan Murdoch wrote:
> 
>> I would say it will be at least a year, and most likely longer.  The
>> tools used to build R haven't been ported to 64 bit Windows yet.
> After
>> those are done (by the MinGW project, not us), we'll need someone with
> a
>> 64 bit Windows machine to handle builds there.
>>
>> Duncan Murdoch
> 
> An additional factor is that MinGW will almost certainly follow the MS
> idea that long's are 4 bytes even under Win64, unlike what every other
> 64-bit OS does.  It will take a fair bit of time and someonw with the
> motivation to do so to sort out the consequences (which may not be
> very great but even establishing that may be non-trivial).
> 
> luke
> 
> 
>