Re: 4GB Physical. Less than 3GB in Linux.

From: Robert Hancock
Date: Mon Apr 16 2007 - 10:33:59 EST


Jeff Chua wrote:
I've noticed that with 4GB physical ram, I'm only see 3098000 MB on
the Dell 745, and 3107056MB on the IBM X60s.

I've tested with CONFIG_HIGHMEM4G=y, CONFIG_HIGHMEM64G=y,
CONFIG_X86_PAE=y, but nothing makes any difference.

Chipset limitation. It uses up most of the MMIO region above 3GB preventing RAM from being mapped there, and doesn't support remapping the covered RAM to above 4GB. Nothing the kernel can do about it.

--
Robert Hancock Saskatoon, SK, Canada
To email, remove "nospam" from hancockr@xxxxxxxxxxxxx
Home Page: http://www.roberthancock.com/

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