But isn't the main purpose of PAE to enable access to memory beyond 4GB, and then only if the app supports it? The only reference I can find for using PAE on a 4GB system is to enable hardware enforced Data Execution Prevention (DEP). I agree about the potential benefits on systems with more than 4GB, in the scenario your describe, but I question its value on a 4GB system. ________________________________ From: thin-bounce@xxxxxxxxxxxxx [mailto:thin-bounce@xxxxxxxxxxxxx] On Behalf Of Malcolm Bruton Sent: Friday, January 12, 2007 2:53 PM To: thin@xxxxxxxxxxxxx Subject: [THIN] Re: Quick PAE question I agree. Not all that bad. If you have servers being constrained by memory you can turn this on to help. As Joe said be ware that it takes memory away form the kernel. i.e. if you have apps with large memory requirements which dictates a handful of users per server it works well. If you are looking to boost users numbers and the apps used only use small amount of memory I doubt you have that much to gain except squeezing on those last few users. Using this setting may dictate that you need to do some kernel memory tweaking as well especially in windows 2000. Brian Madden has an excellent article amount kernel tweaking etc I think it includes PAE etc but I can't find the link. And one last thing. Make sure you test it !!!! Malcolm ________________________________ From: thin-bounce@xxxxxxxxxxxxx [mailto:thin-bounce@xxxxxxxxxxxxx] On Behalf Of Joe Shonk Sent: 12 January 2007 18:53 To: thin@xxxxxxxxxxxxx Subject: [THIN] Re: Quick PAE question It's not all that bad. It does allow for the unused memory that the Servers (not just IBM) grab for PCI-X, etc to be remapped. The bad thing about PAE is it takes away kernel memory space and processing overhead because the OS now has to create a table, map and track that memory. It's a hardware thing, and not really an OS thing. The 3.2 gigs is what is reported when the system POSTs. Joe