I want to use my GPU's ram as a ramdisk, following these instructions : http://en.gentoo-wiki.com/wiki/Using_Graphics_Card_Memory_as_Swap But when I input the " modprobe phram phram=VRAM,0xd8400000,124Mi " command, I get the following error : modprobe: ERROR: could not insert 'phram': Input/output error I use Ubuntu Studio 14.04. Also, is there anyway I could use more than the 128M of prefetchable memory, my GPU has 1GB of ram, I would prefer to use "most" of it.