The memory management whitepaper that I've posted explains all of this: http://www.microsoft.com/whdc/driver/kernel/mem-mgmt.mspx
Pages 9-12 will give you lots of information on physical addressing, bus addressing, how devices can use addresses and so on. Cheers Ken ________________________________ From: Ziots, Edward [EMAIL PROTECTED] Sent: Thursday, 10 January 2008 8:05 AM To: NT System Admin Issues Subject: RE: HP DL380 G5 and Win2k3 R2 Standard not showing maximum memory in OS Mike, I am seeing what you are saying. BIOS in the server I am seeing 3.7GIG only has a NIC card in it, and Dual P4 processors, a Smart Array 6i card. BIOS I am seeing 3.4 GIG has T1 Inte Dialogic Card, Dual NIC’s Smart Array controller, Dual P4 Processors. So the more PCI Type devices it seems that are in the system the less physical memory you are going to have for Windows. NO server has Audio here, no need for it. All servers have CD/DVD drives and SAS or SCsi HD’s. I have seen a system with 4GB of RAM show 3.4GB and a system with over 5GB of RAM show 3.7GB accordingly. So it looks like ordering Enterprise Edition is in the works, since a lot of our application probably aren’t going to be supported on X64 edition by the vendors accordingly. Z ________________________________ From: Mike Gill [mailto:[EMAIL PROTECTED] Sent: Wednesday, January 09, 2008 3:49 PM To: NT System Admin Issues Subject: RE: HP DL380 G5 and Win2k3 R2 Standard not showing maximum memory in OS /PAE won’t do anything with a computer that has only 4GB of mem with an OS that only supports that much memory which include XP and 2K3 STD. It enables extended (Physical Address Extension) address space beyond 4GB. What you’re seeing right now is what you’re supposed to be seeing. These other people that are seeing 4GB reported as available in the Windows > Properties > General tab on STD edition is what is perplexing to me. I would like to think they’re just wrong on something but as I’m not there looking at what they’re looking at, well… Maybe they could call up their MS person and tell them what they’re seeing and ask why they’re seeing it. Because every piece of documentation I’ve read says they shouldn’t be able to do that. As for refuting the DEP thing, again, if these machines are running 2K3 STD and only have 4GB of mem installed then you shouldn’t evar™ see 4GB of physical mem in the task manager or properties dialogue. Answer this. Your machine that shows 3.7GB. Does it have less installed in terms of components? Are more components disabled in the BIOS than other similar machines such as onboard audio, extra NIC’s, or possibly no CD or hard drives? I would make sense if this is true. -- Mike Gill From: Ziots, Edward [mailto:[EMAIL PROTECTED] Sent: Wednesday, January 09, 2008 11:45 AM To: NT System Admin Issues Subject: RE: HP DL380 G5 and Win2k3 R2 Standard not showing maximum memory in OS Thanks for the information, I have boxes that have DEP enabled, and don’t have the /PAE in the boot.ini therefore DEP automatically enabling PAE doesn’t seem to go hand in hand. I got 3 DL 380 G5 that will refute that. Again going to try the /PAE switch on a system and see if anything changes accordingly, as compared to a freshly built system with 4GB in it. I looked at a few other systems, and some of them have 5GB of memory but only Win2k3 STD shows 3.7GB on some and 3.4 on others. Its pretty weird, Z ________________________________ From: Mike Gill [mailto:[EMAIL PROTECTED] Sent: Wednesday, January 09, 2008 1:59 PM To: NT System Admin Issues Subject: RE: HP DL380 G5 and Win2k3 R2 Standard not showing maximum memory in OS Intel machines running 32bit versions of Windows can address 4GB of memory, but not use it. PAE enables address space above 4GB. It’s also required for DEP, and must also be supported by your hardware (e.g. chipset) and drivers. Why some people here are seeing all 4gb in the properties dialogue of 2K3 std, I don’t get it. I thought I understood this issue, but obviously there are some real world experiences here showing otherwise. http://blogs.msdn.com/dcook/archive/2007/03/25/who-ate-my-memory.aspx http://www.microsoft.com/whdc/system/platform/server/PAE/pae_os.mspx http://www.microsoft.com/whdc/system/platform/server/PAE/PAEdrv.mspx http://support.microsoft.com/kb/875352 (DEP) http://tinyurl.com/27obg7 (xp, but still relevant and excellent explanations) PAE on an OS that is limited to 4GB, is only because DEP requires it. Enabling DEP automatically enables PAE. Otherwise it (PAE) would be a useless feature on 2K/XP/2K3 std. The BIOS, video cards, memory, et al, all use address space. When you only have 2GB in the machine, there is a lot of address space left over and unused by the memory you don’t have installed. When you put all 4GB in the machine however, then there isn’t any address space left available for your installed components (video cards, BIOS, drives, et al.) which also use this address space, so something has to give. This is why you see less than 4GB typically. But then there are these people that are seeing the 4GB in Windows and it defy’s what should really be happening as I understand it. Vista 32bit w/ SP1 will report installed memory and not useable memory. So people will see their 4GB, but not actually be able to use it. Weird. -- Mike Gill From: Ken Schaefer [mailto:[EMAIL PROTECTED] Sent: Wednesday, January 09, 2008 12:13 AM To: NT System Admin Issues Subject: RE: HP DL380 G5 and Win2k3 R2 Standard not showing maximum memory in OS http://www.microsoft.com/whdc/driver/kernel/mem-mgmt.mspx Cheers Ken From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Sent: Wednesday, 9 January 2008 4:21 PM To: NT System Admin Issues Subject: RE: HP DL380 G5 and Win2k3 R2 Standard not showing maximum memory in OS We currently have dozens of servers running all flavors of 32 bit OS and we see the full 4 GB give or take a few meg depending on the manuf. I have seen servers only show 3.5 and its always been a BIOS setting in our case that I remember. From: Ken Schaefer [mailto:[EMAIL PROTECTED] Sent: Tuesday, January 08, 2008 6:57 PM To: NT System Admin Issues Subject: RE: HP DL380 G5 and Win2k3 R2 Standard not showing maximum memory in OS Glen, You don’t mention whether you are running x64 or x86 edition of Server 2003. Also, depending on the hardware you have the device you might only “lose” accesss to a few MB of RAM (or maybe none at all). My HP ML330 only loses about 60MB, so instead of 4096 it reports 4036, which looks very similar to 4GB of RAM. But you can disagree all you like – you’d still be wrong :-) Please read the memory management whitepaper I posted earlier if you ‘d like all the details. Alternatively, just read the blog posts from Raymond Chen’s blog if you want some quick information. Cheers Ken ~ Upgrade to Next Generation Antispam/Antivirus with Ninja! ~ ~ <http://www.sunbelt-software.com/SunbeltMessagingNinja.cfm> ~
