I have a Dell box with Intel Xeon E5 2650.
I found that it was missing in hot plug capability. I came to know by reading
the PCIe Express Slot Capabilities Register.
Does there exist any tool or utility by means of which one can
tell whether the board support hot-plug capability or not ?
Try to search through the Linux sources and or documentation.If you are using Windows kernel debugger can be helpful in obtaining bus topology.I am not sure if you can obtain register level granularity.
Hot-add memory minimizes a common source of server downtime: Requiring the server to be powered off and subsequently rebooted during memory upgrades. Hot-add memory allows ranges of physical memory to be added to a running operating system without requiring the system to be shut down. This allows an administrator to add memory to a running system to address existing or future needs for memory without incurring downtime for the system or applications.