quote:
Originally posted by rm rulz
Ok if my new computer has got 4gb of ram (2x2g) in dual channel mode, (keep in mind i have 32bit main OS) since my OS only reads 3.23 gb of my ram can i use the rest of that memory for linux?
Do you have a 64 bit CPU? If you do, you might be able to use all 4 GB. The reason you can't with a 32 bit CPU is that those 32 bits can only address 4 GB of total ram- and some of the ram that needs to be addressed is video ram. Many hardware devices have a little ram (or pretend to), and if it is 'mapped' by the operating system, which allows for fast data transfer, and userspace drivers, that eats away at the 4 GB total. so the 3.23 GB is what is left after mapped I/O regions are taken out of the 32-bit address space.
a 64 bit CPU has a much larger address space, but to take advantage of this, the CPU needs to be in 64 bit mode. Running a 64 bit operating system will give you access to all of your ram. However, running a 64 bit operating system *in a VM* will not. You could do it the other way, and run MS Windows in a VM. If you've got a CPU with virtualisation instructions, you can do this with Xen. Just make sure your copy of Xen is compiled for your architecture.
ShawnZ: actually, x86-64 only supports address spaces up to 512 Terabytes, as only 48 bits are relevant, but they have room to fix that.
was put impeccably into words at DebianDay for me last Saturday, by Knut Yrvin of Trolltech - adults try something once, fail, and then are like "ffs this doesn't work". Children try, fail, and then try again, and succeed - maybe on the second, or even fifth retry. But the thing is that they keep at it and overcome the problems in the end.
-andrewdodd13
