How much memory can SQL Enterprise use?

Hi,
I've heard that SQL Enterprise can use up to 4gigs of RAM. Windows 2000
Server can address up to 4gigs of RAM in a single process, but since 2gigs
of that address space is "reserved" -- this means that SQL Server Enterprise
can really only use a maximum 1.7 to 2 gigs of RAM in the SQL Server process
when running on Win2000... My question is: If I install Windows 2003 and
stick SQL Enterprise on that machine, how much memory will SQL be able to
use (in a given process). MSFT's site says that Win2003 can make use of 4
gigs of memory, but will I run into the same problem that Win2000 has in so
far as the first 2gigs of the process' virtual memory space is "reserved"?
Thanks.
DavidSQL Server under W2K Advanced server can use up to 8 GB of
RAM. Under W2K Datacenter it is 32 GB. With W2K3
Enterprise Edition it's 32 GB for 32-bit, 64-bit is 64 GB.
(And so on ...)
To use the advanced memory under 32-bit, you need to use
the /PAE switch and turn AWE on in SQL Server. However,
the memory is not dynamic - it is a fixed static amount.
Under 64-bit, all memory is dynamic.
If you need > 2 GB for SQL but not more then 3 GB, you do
not have to enable /PAE or AWE, but just set /3GB in the
OS, and SQL Server can use up to 3 GB with no problem.
These are the ways you get SQL Server to recognize more
than 2 GB of memory.
>--Original Message--
>Hi,
> I've heard that SQL Enterprise can use up to 4gigs of
RAM. Windows 2000
>Server can address up to 4gigs of RAM in a single
process, but since 2gigs
>of that address space is "reserved" -- this means that
SQL Server Enterprise
>can really only use a maximum 1.7 to 2 gigs of RAM in the
SQL Server process
>when running on Win2000... My question is: If I install
Windows 2003 and
>stick SQL Enterprise on that machine, how much memory
will SQL be able to
>use (in a given process). MSFT's site says that Win2003
can make use of 4
>gigs of memory, but will I run into the same problem that
Win2000 has in so
>far as the first 2gigs of the process' virtual memory
space is "reserved"?
>Thanks.
>David
>
>.
>|||Thanks for the information. I've done a bit of research regarding the
PAE and 3GB switches that you've mentioned and I have a few followup
questions/comments:
- First of all, it appears that these switches aren't available in the
standard version of W2K Server. The Advanced version (or greater) is
required. Is there a smooth upgrade path from standard W2K Server to
Advanced? In other words, can I just install advanced on top of my current
W2K Server, or must I format the drive and do a clean installed of Advanced?
- /PAE is an OS-specific switch, not SQL-specific. Setting this switch
means that the OS can address more than 4 gigs of physical memory. Is this
correct?
- /3G is an OS-specific switch. Setting this switch means that a given
process can access a maximum of 3 gigs of memory as opposed to the standard
2 gigs of memory. Could you please elaborate on this switch? It seems
partially redundant to /PAE. If I've switched on /PAE, why would I want /3G?
- AWE isn't a switch, but an API that can be used by individual
applications such as SQL Server. SQL Server uses AWE to address memory
beyond 4gigs. The memory is reserved for exclusive access by the AWE client
(in my case, SQL Server). Is this correct?
So for a machine that has 6 gigs of RAM:
- I *do* need the /PAE switch because the OS needs to address beyond 4
gigs of RAM.
- I *do* need SQL Server to run in AWE mode because it needs to access
to more than 4 gigs of RAM.
- Do I need /3gb?
Thanks for the clarification...
David
"Allan Hirt" <allanh@.NOSPAMavanade.com> wrote in message
news:09c201c3a9a8$97307100$a301280a@.phx.gbl...
> SQL Server under W2K Advanced server can use up to 8 GB of
> RAM. Under W2K Datacenter it is 32 GB. With W2K3
> Enterprise Edition it's 32 GB for 32-bit, 64-bit is 64 GB.
> (And so on ...)
> To use the advanced memory under 32-bit, you need to use
> the /PAE switch and turn AWE on in SQL Server. However,
> the memory is not dynamic - it is a fixed static amount.
> Under 64-bit, all memory is dynamic.
> If you need > 2 GB for SQL but not more then 3 GB, you do
> not have to enable /PAE or AWE, but just set /3GB in the
> OS, and SQL Server can use up to 3 GB with no problem.
> These are the ways you get SQL Server to recognize more
> than 2 GB of memory.
> >--Original Message--
> >Hi,
> >
> > I've heard that SQL Enterprise can use up to 4gigs of
> RAM. Windows 2000
> >Server can address up to 4gigs of RAM in a single
> process, but since 2gigs
> >of that address space is "reserved" -- this means that
> SQL Server Enterprise
> >can really only use a maximum 1.7 to 2 gigs of RAM in the
> SQL Server process
> >when running on Win2000... My question is: If I install
> Windows 2003 and
> >stick SQL Enterprise on that machine, how much memory
> will SQL be able to
> >use (in a given process). MSFT's site says that Win2003
> can make use of 4
> >gigs of memory, but will I run into the same problem that
> Win2000 has in so
> >far as the first 2gigs of the process' virtual memory
> space is "reserved"?
> >Thanks.
> >
> >David
> >
> >
> >.
> >