The switch is no relevant to 64 bit platforms. On 32 bit platforms, any process can address 4 GB memory (this is 2^32 bytes), but has the right to use only the lower 2 GB (minus some kylobytes at the start and the end, for boundery checking). The upper 2 GB are reserved for the OS. The the /3GB switch changes this ratio to 3 GB user addressable space and 1 GB for the OS. This is address space per process, no actually consumed memory - even Notepad has the same address space, private for it's process. I have used this switch on many servers without any issue. On 64 bit platforms any process can address much more memory. So the switch does not work - it is not needed. -- Regards, Yavor Ivanov Senior Database Expert Stemo Ltd On Tue, 17 Jul 2007 02:51:58 +0300, William Wagman <wjwagman@xxxxxxxxxxx> wrote: > Allen, >Does this hold true for 64-bit Windows as well? Until seeing this thread > I was unaware of the /3GB switch available for windows. It sounds > analogous to compiling in the hugemem kernel in Linux. Or are the two > unrelated? On Technet so far the only document I have found is the > 32-bit Oracle Database Platform Guide, chapter 1. Can you point out a > good source of information on this please. >Thanks. > > Bill Wagman > Univ. of California at Davis > IET Campus Data Center > wjwagman@xxxxxxxxxxx > (530) 754-6208 > > > ________________________________ > > From: oracle-l-bounce@xxxxxxxxxxxxx > [mailto:oracle-l-bounce@xxxxxxxxxxxxx] On Behalf Of Allen, Brandon > Sent: Monday, July 16, 2007 3:07 PM > To: saints.richard@xxxxxxxxx; oracle-l@xxxxxxxxxxxxx > Subject: RE: Oracle on Windows 2000 AS with /3GB flag > > > I always use the /3G flag on all Windows database servers - for both > Oracle and SQL Server. I've used it several times on different > combinations of Windows, SQL & Oracle versions and never had any > problems. >Regards, > Brandon > > Privileged/Confidential Information may be contained in this message or > attachments hereto. Please advise immediately if you or your employer do > not consent to Internet email for messages of this kind. Opinions, > conclusions and other information in this message that do not relate to > the official business of this company shall be understood as neither > given nor endorsed by it. > > -- //www.freelists.org/webpage/oracle-l