 | | | physical memory support under RHEL for Opteron | physical memory support under RHEL for Opteron 2004-04-01 - By Rick Stevens
Back
Guy Rouillier wrote:
> On Wed, 31 Mar 2004 11:52:32 -0800
> Rick Stevens <rstevens@(protected) > wrote:
>
>
> >Chiu, PCM (Peter) wrote:
> >
> > >Hi,
> > >
> > >I am just about to order an dual Opteron 248 server to run under RHEL AS.
> > >
> > >I would like to double check the physical memory supported - we are getting
> > >8 x 2GB PC3200 or PC2700 memory on this server.
> > >
> > >I have found something a bit obscure on the RH web page:
> > > ___
http://www.redhat.com/software/rhel/as/_
> > >
> > >in that it said:
> > >
> > >**** 64GB is the maximum memory size for X86 systems. Maximum memory
> > >sizes vary with other architectures.
> > >
> > >Can anyone confirm
> > >a. the maximum memory size for Opterons supported, and
> > >b. the maximum usable physical memory per process on user applications
> >
> >As I understand it, RHEL AS3 is available only as an x86 package (in
> >other words, 32-bit). As such, it is limited to the same 64GB limit as
> >any 32-bit OS. The per-process limit is 2^32 bytes (4GB).
>
>
> We just got this at work in order to run an AMD64 version of Oracle. See the following: RH makes an AMD64-specific version of AS3, which is 64-bit. Something is strange about the chart on that page, as they claim 64 GB on x86 but on 16 GB on AMD64. How can you get > 4 GB physical memory on 32-bit hardware? Are they talking about Intel 's PAE?
It 'd sure be nice if you 'd wrap your message lines at 72 characters or
so.
The AMD 64 chip has a 40-bit physical address space with a 48-bit
virtual address space. The 40-bit address space gives you 1TB of RAM,
the 48-bit virtual space gives you 280TB of address space. I rather
doubt you 'll find any motherboard in the near future that provides that
kind of RAM support for less than thousands of dollars.
I still don 't know what AS3 on an X86_64 provides. If they use the full
48-bit address space for apps, then a process has access to 280TB of
memory.
-- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- --
- Rick Stevens, Senior Systems Engineer rstevens@(protected) -
- VitalStream, Inc.
http://www.vitalstream.com
-
- -
- "I 'd explain it to you, but your brain might explode. " -
-- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- --
__ ____ ____ ____ ____ ____ ____ ____ ____ ____
Redhat-install-list mailing list
Redhat-install-list@(protected)
https://www.redhat.com/mailman/listinfo/redhat-install-list
To Unsubscribe Go To ABOVE URL or send a message to:
redhat-install-list-request@(protected)
Subject: unsubscribe
|
|
|