8G RAM in 32bit platform

[A J Thew]

On 7/13/07, Patrick T. Tsang <patrick at patricktsang.net> wrote:
> Hello,
>
> Sorry, I didn't mention it is Redhat AS5.0
>
> The bigsmp no longer exists.

I thought the 5 kernels were PAE by default now (?)

Alan Thew
>
> Anyone tried 32bits Redhat AS5.0 with 8G RAM for cyrus imapd?
>
> Thanks
> Patrick
>
>
>
> ----- Original Message -----
> From: "David Carter" <dpc22 at cam.ac.uk>
> To: "Patrick T. Tsang" <patrick at patricktsang.net>
> Cc: <info-cyrus at lists.andrew.cmu.edu>
> Sent: Friday, July 13, 2007 5:24 PM
> Subject: Re: 8G RAM in 32bit platform
>
>
> > On Fri, 13 Jul 2007, Patrick T. Tsang wrote:
> >
> >> We will start up the mail server with 4G RAM.
> >> As I know the 32bits cannot handle RAM more than 3.2G.
> >>
> >> The client plans to upgrade the RAM to 8G in coming years.
> >> Can the 64bits platform is the only solution to it?
> >
> > You don't say which CPU or operating system you are using.
> >
> > The Linux bigsmp kernel supports PAE extensions on IA32 platforms: all 8
> > GBytes will be available as buffer cache, which is what matters to Cyrus.
> >
> > 64 bit pointers don't really do anything: no single process in Cyrus needs
> > 2 GBytes of address space. 64 bit integer arithmetic would be a slight
> > benefit for quota arithmetic (unsigned long long). However my systems
> > spend about 2% of their time in user CPU state according to vmstat. You
> > really aren't going to notice on any modern Intel/AMD CPU.
> >
> > --
> > David Carter                             Email: David.Carter at ucs.cam.ac.uk
> > University Computing Service,            Phone: (01223) 334502
> > New Museums Site, Pembroke Street,       Fax:   (01223) 334679
> > Cambridge UK. CB2 3QH.
> >
>
> ----
> Cyrus Home Page: http://cyrusimap.web.cmu.edu/
> Cyrus Wiki/FAQ: http://cyrusimap.web.cmu.edu/twiki
> List Archives/Info: http://asg.web.cmu.edu/cyrus/mailing-list.html
>