maximum memory capacity

[Joel Jaeggli]

On Mon, 26 Jan 2004, Chiu, PCM (Peter)  wrote:

> Thanks, my understanding on 32-bit based platforms, the limitation is 4GB.

linux on x86 can support up to 64GB of ram... address space is 4GB so not
all of it gets permently mapped... kernels aren't generally compiled for
64GB because the address extensions will prevent the kernel from booting
on cpu's that don't support it... that said you'll have a fair performance
tradeoff to consider with more than 4GB of ram (3%-6% more overhead 
depending on the application). also the most memory an individual process 
can use is 3GB of ram.
 
> Opterons or Itanium can lift this limitation.

The opteron's long mode supports 1TB of addressable memory the current 
2.6.X support 512GB as I understand it... populating an opteron mainboard 
with more than 16-20GB of ram (tyan s4880 has 10 dimm sockets) is left as 
an exerercise for the reader.

> But not sure what their latest status.
> 
> Peter
> -----Original Message-----
> From: fedora-list-admin at redhat.com [mailto:fedora-list-admin at redhat.com] On
> Behalf Of WipeOut
> Sent: 26 January 2004 15:02
> To: fedora-list at redhat.com
> Subject: Re: maximum memory capacity
> 
> 
> Chiu, PCM (Peter) wrote:
> 
> >Can anyone tell me the maximum physical and virtual memory sizes 
> >supported under FC1?
> >
> >I am trying to work out the technical differences between RHES and FC1 
> >to enable us to choose the appropriate version to use.  I am aware of 
> >the initial licenses and maintenance issues.
> >
> >Many Thanks.
> >
> >Peter
> >
> >
> >  
> >
> Something says to me that the standard Fedora kernel is setup for 4GB (I 
> amy be wrong).. But there is nothing stopping you building a kernel for 
> larger amounts of memory..
> 
> later..
> 
> 
> 

-- 
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Joel Jaeggli  	       Unix Consulting 	       joelja at darkwing.uoregon.edu    
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