bump up Alienware 18 to to 64GB ram

I have an Alienware 18 18.4­Inch Gaming Laptop, 4th Gen 2.5 GHz Intel Core i7­4710MQ Processor, 32GB DDR3, 512GB SSD + 1TB HDD, Dual AMD Radeon R9 M290X

I use it to develop Android apps and occasionally some Visual Studio work. I want to bump it up to 64 or 128GB of ram. basically i want my dev environments to load, run tests etc faster.

How can i tell what the upper limit of memory capacity is on this beast?

so that i know whether to get 64gb, 128gb or if its possible at all.