[r] Increasing (or decreasing) the memory available to R processes

I would like to increase (or decrease) the amount of memory available to R. What are the methods for achieving this?

Microsoft Windows accepts any memory request from processes if it could be done.

There is no limit for the memory that can be provided to a process, except the Virtual Memory Size.

Virtual Memory Size is 4GB in 32bit systems for any processes, no matter how many applications you are running. Any processes can allocate up to 4GB memory in 32bit systems.

In practice, Windows automatically allocates some parts of allocated memory from RAM or page-file depending on processes requests and paging file mechanism.

But another limit is the size of paging file. If you have a small paging-file, you cannot allocated large memories. You could increase the size of paging file according to Microsoft to have more memory space.

For linux/unix, I can suggest unix package.

To increase the memory limit in linux:

install.packages("unix") 
library(unix)
rlimit_as(1e12)  #increases to ~12GB

You can also check the memory with this:

rlimit_all()

for detailed information: https://rdrr.io/cran/unix/man/rlimit.html

also you can find further info here: limiting memory usage in R under linux

Use memory.limit(). You can increase the default using this command, memory.limit(size=2500), where the size is in MB. You need to be using 64-bit in order to take real advantage of this.

One other suggestion is to use memory efficient objects wherever possible: for instance, use a matrix instead of a data.frame.

1. Buy more ram
2. Switch to a 64-bit OS. Combine with point 1.

To increase the amount of memory allocated to R you can use memory.limit

memory.limit(size = ...)

Or

memory.size(max = ...)

About the arguments

• size - numeric. If NA report the memory limit, otherwise request a new limit, in Mb. Only values of up to 4095 are allowed on 32-bit R builds, but see ‘Details’.
• max - logical. If TRUE the maximum amount of memory obtained from the OS is reported, if FALSE the amount currently in use, if NA the memory limit.

In RStudio, to increase:

file.edit(file.path("~", ".Rprofile"))

then in .Rprofile type this and save

invisible(utils::memory.limit(size = 60000))

To decrease: open .Rprofile

invisible(utils::memory.limit(size = 30000))

save and restart RStudio.