I tried to convert large (~180MB) .xyz file into vector through v.in.ascii in QGIS Brighton (2.6.0) Grass plugin (it should be Grass version 6.4.3). The "primitive registration" stage lasted very long and then ended with following error: `G_realloc: unable to allocate 46320000 bytes of memory at cindex.c:108`. It seems that GRASS can't allocate more than ~45MB of input data; 45MB is tiny compared to my RAM of 2GB, so the problem is probably caused by some limit in GRASS or in QGIS, and probably related specifically to `v.in.ascii` method, because `r.in.xyz` worked and didn't throw this problem. 

Why is there such a limitation, and how to bypass it?

According to a comment in [a related question][1], this problem should be fixed in Grass 7. However, I wish to use GRASS in the QGIS plugin form, and it will take months before it will be upgraded to GRASS 7.

Is there any way how to solve it with GRASS 6?

OS: Windows 7 (64-bit)  
QGIS architecture: 32-bit  
SWAP file: 4096MB

I doubled the SWAP file size and the error is the same.

  [1]: https://gis.stackexchange.com/q/8418/12768