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Documentation / memory.txt


Based on kernel version 3.6.1. Page generated on 2012-10-11 09:35 EST.

1	There are several classic problems related to memory on Linux
2	systems.
3	
4		1) There are some motherboards that will not cache above
5		   a certain quantity of memory.  If you have one of these
6		   motherboards, your system will be SLOWER, not faster
7		   as you add more memory.  Consider exchanging your 
8	           motherboard.
9	
10	All of these problems can be addressed with the "mem=XXXM" boot option
11	(where XXX is the size of RAM to use in megabytes).  
12	It can also tell Linux to use less memory than is actually installed.
13	If you use "mem=" on a machine with PCI, consider using "memmap=" to avoid
14	physical address space collisions.
15	
16	See the documentation of your boot loader (LILO, grub, loadlin, etc.) about
17	how to pass options to the kernel.
18	
19	There are other memory problems which Linux cannot deal with.  Random
20	corruption of memory is usually a sign of serious hardware trouble.
21	Try:
22	
23		* Reducing memory settings in the BIOS to the most conservative 
24	          timings.
25	
26		* Adding a cooling fan.
27	
28		* Not overclocking your CPU.
29	
30		* Having the memory tested in a memory tester or exchanged
31		  with the vendor. Consider testing it with memtest86 yourself.
32		
33		* Exchanging your CPU, cache, or motherboard for one that works.
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