Re: AMD Athlon64 X2 Dual-core and 4GB

From: Eric W. Biederman
Date: Fri Oct 28 2005 - 11:15:19 EST


thockin@xxxxxxxxxx writes:

> On Fri, Oct 28, 2005 at 09:30:51AM -0600, Eric W. Biederman wrote:
>> > Thus, the question - would I be able to use whole 4G RAM with dual-core amd
> and
>> > kernel with SMP compiled for i686?
>
> Why would you use a dual core AMD in 32 bit mode? Just build an x86_64
> kernel.
>
> If you want to use 4GB in 32 bit mode, you *need* remapping (or you lose
> part of your memory). Remapping means you have MORE than 4 GB of physical
> address, which means you need PAE to use it at all.

Yes, and PAE works fine with a 32bit kernel. I agree it is a silly
configuration and a 64bit kernel would use the memory more
efficiently. My basic point was that a dual-core is a recent enough
processor from AMD that it supports memory remapping. So with a
correct BIOS there should be no problems.

Eric

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/