Re: [gentoo-user] Linux too damn slow if memory > 3GB

[Tim Allingham <deserted@westnet.com.au>]

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On Sat, 2007-07-28 at 20:28 -0300, Daniel van Ham Colchete wrote:
> Hello everyone!!!
> 
> May be somebody can shed some light here... I'm building a server here
> with 4GB of RAM memory. The fact is, if I boot with mem=3072M
> everything goes as fast as it should but I'm not using 1GB of memory.
> If I don't put the mem option, Linux will see 4GB of memory available
> but it will be damn slow (really). 
> 
> To make Linux recognize 4 gigs of memory I had to activate
> HIGHMEM=64GB, otherwise it only recognizes 3279MB (but it is fast).
> 
> My processor is a Intel Core 2 Duo E6320 (1.86Ghz). The motherboard is
> Intel. I'm running Gentoo at 32bits mode and the kernel version is
> 2.6.20-gentoo-r8.
> 
> Any lights would be very appreciated.
> 
> Best regards,
> Daniel Colchete

I don't actually run 4GB of RAM in any of my intel systems, so I can't
comment from experience, however my suspicion would be the overhead
introduced from PAE, which (at least on older kernels) requires some
processing overhead to utilise.  Are you able to try a 64-bit install to
determine if this is the case?

Regards,

Tim Allingham
Email:Tim@DataFirst-IT.com.au

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