If PAE is enabled, with 32gb memory availabe, is it necessary to include the
/3GB switch in the boot.ini in order for AS to address 3gb of memory?

Thanks...

Michael

Yes it is. Without the 3Gb switch the server process will still be
limited to 2Gb of addressable memory.

--
Regards
Darren Gosbell [MCSD]
<dgosbell_at_yahoo_dot_com>
Blog: http://www.geekswithblogs.net/darrengosbell

Thanks for the answer...

What sucks about that is that if you buy a 32-bit 16way Unisys server that
has 32gb of physical memory, AS is still limited to 2gb because there is a
PAE - /3GB conflict. From what I understand, and have seen personally, is
that if you have more than 16gb of memory with the /3GB switch and the PAE
enabled, usually hot swappable memory automatically enables PAE, your Kernel
crashes because it needs more than 1gb of memory to handle more than 16gb of
memory. And to make matter worse, AS uses formulas to calculate memory and
thread configurations that are too much for the 2gb limit...

So, we have established that you have to use the /3GB switch for the process
to use more than 2gb… Is there a way to fool the process by using /USERVA
switch with the /3GB switch to give the kernel more memory to handle more
than 16gb of memory and still have the process use 3gb?

And, from what I’m understand is that SQL Server relational engine gets
around this with the AWE configuration, correct?

Thanks again…

Michael


"Darren Gosbell" wrote:

with more then 16Gb, the /3gb option is not required, only the /pae option
is needed.


"BATMAN" <BATMAN (AT) discussions (DOT) microsoft.com> wrote

This matches my understanding. If you have more than 16Gb, you need to
use /PAE and cannot use /3Gb. This is because /3Gb takes the extra 1Gb
from memory that is normally allocated to the kernel. When you have more
than 16Gb of RAM, the kernel needs more than the 1Gb it gets when the
/3Gb switch is on.

On some of the Unisys servers you can split off some of the
RAM/processors to treat them as a separate box, but obviously this
reduces the peak scale up capability of the box. licensing should be
similar though if you are using a per processor model.

You are correct.

From what I understand /USERVA is a new switch to Win2k3. I haven't had
to use it myself as I have been lucky enough that my 2 biggest clients
have both jumped straight to 64bit.

--
Regards
Darren Gosbell [MCSD]
<dgosbell_at_yahoo_dot_com>
Blog: http://www.geekswithblogs.net/darrengosbell