We have 2 instances on a box with 32 GB of RAM. When we set max memory on
each, do we want to give each say 30GB leaving 2GB for OS or do we give each
instance say 15GB with a total of 30GB?

If you only have 32GB total how do you expect both instances to use 30GB
apiece? Is this X64 bit or 32 bit? Is this SQL 200 or 2005 and what
edition?

--
Andrew J. Kelly SQL MVP
Solid Quality Mentors


"RR" <rf@test.com> wrote in message
news:O022XDguIHA.4376@TK2MSFTNGP06.phx.gbl...
> We have 2 instances on a box with 32 GB of RAM. When we set max memory on
> each, do we want to give each say 30GB leaving 2GB for OS or do we give
> each instance say 15GB with a total of 30GB?
>

With 32GB of RAM, I'd typically want to leave 4GB for OS and other processes.
No hard empirical data to support why 4GB, just me being cautious. And if SQL
Server needs more memory, I'd opt for adding more memory instead trying to
squeeze a GB or two out of OS.

Linchi

"RR" wrote:

> We have 2 instances on a box with 32 GB of RAM. When we set max memory on
> each, do we want to give each say 30GB leaving 2GB for OS or do we give each
> instance say 15GB with a total of 30GB?
>
>
>

On May 20, 6:07am, Linchi Shea <LinchiS...@discussions.microsoft.com>
wrote:
> With 32GB of RAM, I'd typically want to leave 4GB for OS and other processes.
> No hard empirical data to support why 4GB, just me being cautious. And if SQL
> Server needs more memory, I'd opt for adding more memory instead trying to
> squeeze a GB or two out of OS.
>
> Linchi
>
>
>
> "RR" wrote:
> > We have 2 instances on a box with 32 GB of RAM. When we set max memory on
> > each, do we want to give each say 30GB leaving 2GB for OS or do we give each
> > instance say 15GB with a total of 30GB?- Hide quoted text -
>
> - Show quoted text -

Hi ,

As andrew said you can't give all to both instances. When you have
named instances running definitely the resources cpu, memory are going
to divide and will have its own share.


Thanks
Ajay Rengunthwar
MCTS

Also don't forget that MAX MEMORY setting just controls the BUFFER pool of
memory. Lots of other sql stuff use their own RAM. So 14GB for one, 14GB
for the other may make you THINK you have left 4GB for the OS, but you
really haven't. You would need more like 12 an 12 I bet. Monitor pages/sec
in perf mon to see if you are getting paging, which is an indication that
too much memory is allocated to stuff.

--
Kevin G. Boles
Indicium Resources, Inc.
SQL Server MVP
kgboles a earthlink dt net


"RR" <rf@test.com> wrote in message
news:O022XDguIHA.4376@TK2MSFTNGP06.phx.gbl...
> We have 2 instances on a box with 32 GB of RAM. When we set max memory on
> each, do we want to give each say 30GB leaving 2GB for OS or do we give
> each instance say 15GB with a total of 30GB?
>