Ram timing difference

[lakshan.vc]

What is the "Pc3 12800U 11-11-b2' ram and "Pc3 12800U11-11-b1" ram differences. It can works together duel chanal slots?

 

[brispuss]

The difference between the two modules is due to a slight change in design of the module.

These modules might or might not work together due to variations in module characteristics (apart from timings, voltage and frequency). You could try them and see if they work together.

Ideally, two modules from the same dual channel kit should be used, as these modules have been tested and are guaranteed to be compatible with each other. Trying individual modules not from the same dual channel kit (as seems to be the case here) is always a gamble; in this case the modules might or might not work together.