Vista - Vista Business x64 looses 15% of Physical Ram after Update?

Greetings,

I'm running a Dell Poweredge 1900 (Quad-core Xeon 2.33 with 4GB ram) as a desktop box with Vista Business x64. (I know I know - it's not designed to be used that way...but it works great).

After installing the seemingly-innocuous Windows Updates this morning (7/11/2008) I'm suddenly getting errors that my RAM is running low. I'm running the same exact applications that I've been using for some time now without any problems. (One of the applications is a Microsoft Virtual PC that I've allocated about 2GB - that's why I'm even close to running low with 4GB.)

The updates from this morning were the typical Windows Defender definitions, an updated Malicious Software Removal tool, a fix for Outlook 2007 (which I don't currently use) and a Vista update that supposedly added some words to the Spell-check dictionary for German language...(although I'm using English).

Further investigation reveals that my task manager claims that I'm using 85% Physical memory (in status bar at bottom) but the Physical Memory group box indicates that I have 0MB free!

It's odd that something like this would suddenly change after working so smoothly for so long. And what could be hiding that extra 15% of physical ram??

Any ideas?
Thanks in advance,
mark

Did you shutdown and restart? What process is tying up the RAM?

Thanks for your quick response!

Sorry - I should have specified earlier. I've done a full restart several times (I always do it on a daily basis anyway).

Other than the typical MS Virtual PC process there does not appear to be any other process consuming a substantial amount of RAM. IE is using 133MB, svchost is using 88MB, VPC (console) is using 58MB, and the remaining processes are in single digits.

Odd indeed! I'll keep digging..

I thought I was on to something when I remembered that I installed TrueCrypt 6.0 (TrueCrypt - Free Open-Source On-The-Fly Disk Encryption Software for Windows Vista/XP, Mac OS X and Linux) late yesterday. Further investigation (and uninstalling TrueCrypt) left me in the same place - no explanation.

I've attached a screenshot of my Task Manager. What seems odd to me is that the Physical Memory at the bottom reads 86% (as well as the Memory graph), but the Physical Memory group box indicates that Free memory is only 1MB.

It seems like I should have around 575MB free if the 86% is accurate. Am I just misunderstanding what these numbers represent? (I'm a developer - not a system administrator...)

Thanks in advance for your help!

My workstation uses 12% of the ram. Its paging is 16GB. I have 16GB of RAM. That does not look bad at 86%. I will check my Vista x64 Ultimate tonight and post a screen shot of it.

Thanks, Michael!

I suppose what's so odd about this is that the RAM usage suddenly changed. Unfortunately, I don't have a baseline of real numbers to use for comparison - only less accurate things like knowing how many applicaitons I could run at once.

But I'm certain that something has changed. It's easy to blame the Windows Update... :-)

Vista uses RAM and paging differently than XP. Under a heavy load it should return the RAM to applications. You could disable index services and see if that helps. Personally, I would leave it alone.

I think I've found the problem as well as a good solution.

I'm not sure how this happened, but the Virtual Memory / Paging was completely disabled. I haven't touched any of those settings for months...

I re-enabled paging (System Managed) and everything seems to be back to "normal" now. Since I'm using 4 HDDs in RAID 5 (with 3 logical drives), I didn't particularly think it mattered which drive partition held the page file.

Thanks again for the quick responses, Michael!