- Limitation in terms of resources
- OS design and 32 bit platform
- Slow performance when high paging occurs
Limitation in terms of resources:
When to display more than 200K results correctly, not only for searching and displaying even when user goes through the search results, small operations like user scrolling down the search results etc would require many pages move in and out of physical memory and this would cause performance related issues depending on the amount of physical memory on the machine and the page file configuration. (you may need to configure high page file on the clients just for this reason)
OS Design (X86 architecture) related limitations:
On 32 bit platform, OS can only access 4GB of physical memory (32 bit communication so 2 to the power of 32 = 4Gegs of memory) This is also called Windows 32-bit flat memory model.
So all windows operating systems run on 32 bit architecture to work on 4GB of virtual memory architecture and no application would have direct access to physical memory.
The address space is usually split so that 2 GB of address space is directly accessible to the application and the other 2 GB is only accessible to the Windows executive software (also called as user mode for applications and Kernel mode)
Memory Support and Windows Operating Systems http://www.microsoft.com/whdc/system/platform/server/PAE/PAEmem.mspx
So even desktop search tools, which run as a process would have 2GB of user mode memory that it needs to utilize for its own purpose. During the conditions of displaying high amounts to search results which are above 2GB, it simply CANNOT.
This is not desktop search software related limitation but this is the way the Operating System has been designed.
Slow Performance while high paging occurs:
There is no need to explain this in detail, as if need to display more results then more paging needs to be done, and this relatively means that data communication from faster memory to relatively less faster memory which is physical disk. If we need extensive paging, then this is going to hit performance of the machine.
