We have an application which does the following major tasks
1. User Interface sevicing through RunUserInterface(main thread)
2. Async Timer running at 100 msec to update the date received from a device
3. A device interrupt callback function to trigger certain actions(The driver for the devices expects a function pointer which will be called on completion of certain activity by the device). The interrupt happens once every 5 msec.
The application was found to be working fine in a Pentium Quad Core machine with 4 GM RAM and Windows 7 Ultimate as the OS. The jitter observed in 5 msec is between 4 and 6 msec which is quite ok for the application.
But when the same application is loaded in two laptops with Pentium i5 procesor with 4GB RAm loaded with Windows 7 Home Basic & Windows 7 Professional respectively, the jitter that are observed is quite high reaching upto even 20 msec. Specifically, the jitter is more when there are some user operations.
What could be the reason for the variation for the jitter? It is important that we need to service the interrupt from the device atleast within the 5 msec.
Any suggestions would help.
Thanks
