Here's mine...

Lightroom version: 4.0 [814577]

Operating system: Windows 7 Business Edition

Version: 6.1 [7601]

Application architecture: x64

System architecture: x64

Physical processor count: 2

Processor speed: 2.5 GHz

Built-in memory: 4047.8 MB

Real memory available to Lightroom: 4047.8 MB

Real memory used by Lightroom: 672.0 MB (16.6%)

Virtual memory used by Lightroom: 715.3 MB

Memory cache size: 457.3 MB

System DPI setting: 96 DPI

Desktop composition enabled: Yes..

Displays: 1) 1280x800

As you can see the memory usage isn't that high.  Is your windows 7 64bit?  Your architecture says x86 whereas mine says x64...  Not sure if that may help you get in the right direction or not...

I wonder if that's why?  Here's the system requirements.

  System requirements

Windows

• Intel® Pentium® 4 or AMD Athlon® 64 processor
• Microsoft® Windows Vista® with Service Pack 2 or Windows® 7 with Service Pack 1
• 2GB of RAM
• 1GB of available hard-disk space
• 1024x768 display
• DVD-ROM drive
• Internet connection required for Internet-based services*

Now they don't actually state 64bit OS in this however I've heard it stated that it is a requirement.  It'd be worth a call to Adobe...

GKN 100 wrote:

 

any ideas what I should do to improve performance.

You should switch to using the 64-bit version of W7.

Adobe KB states that on a 32-bit system LR can only use 2GB of memory, but I started seeing problems when LR memory usage exceeded 1GB.

Now I'm on a 64-bit W7 and LR typically uses over 2,1 GB of memory.

You don't have to buy a new W7 licence. One licence is good for either version as long as you don't use them on different computers simultaneously.

If you have 3GB of memory, you also want to make sure that your swap file size is at least double the memory. And of course fixed size and unfragmented.

But you should consider installing the maximum amount of memory the motherboard can support.