Hi colom93,

A computer memory upgrade is often the best value for increasing overall computer performance.

Yes the maximum amount of memory on Inspiron N5110 is  8GB.

The Inspiron N5110 / 15R system supports dual-channel DDR3 SDRAM with memory speeds of 1333 MHz. At 1333 MHz, the memory offers a significant increase of memory performance over previous platforms.

• The memory solution is implemented in a dual-channel configuration, allowing the system to have twice the memory bandwidth while using the same memory technology.
• Memory modules must be installed as a perfectly matched pair to take advantage of the dual-channel memory bus. If not a matched pair, the system's memory bus operates in a single-channel configuration.

I have provided memory configurations below:

Basically, when both DIMM connectors are populated, the system has optimum dual-channel performance unless channels A and B have different amounts of memory.

Try below combinations for better performace:

Please let me know if you have any other queries.

Best to get RAM from crucial.

http://www.crucial.com/store/listparts.aspx?model=Inspiron%20N5110

Sometimes there is a problem using other RAM from other manufacturers and hence most of us recommend using crucial with a Dell.

As you see the Inspiron N5110 has 2 slots, maximum memory stated by Dell /Crucial is 8 GB (sometimes people can get away with installing more then maximum, other times the system won't boot or it isn't able to use the additional RAM).

Generally its best to install RAM in matching pairs which is why crucial tend to sell kits e.g. in your case a 2×4 GB kit. Therefore there is no existing RAM modules. Otherwise installing modules at a different speed will cause all modules to run at the lowest speed.